题目内容
（请给出正确答案）
The pressure of a liquid leaving the pump can be referred to as the ______.
A.total head
B.discharge head
C.net positive suction head
D.suction head
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更多“The pressure of a liquid leavi…”相关的问题
第1题
Air entering an air-cooled refrigeration system is indicated by _____.
A.frosting of the liquid line
B.higher than normal head pressure
C.a clear sight glass
D.abnormally cold reefer boxes
第2题
听力原文： More than 50 percent of all homes in the U.S. have one thing in common; people living in them keep one or two small animals as pets. In fact there are more pets in the U.S than children. Why？
Researchers have been attempting to find the scientific answer to this question. Much has been written about how animals, violent crimes, and about how they help children deal with emotional problems.
Last year researchers met at the America's National Institute of Health. They found there is a lot of evidence that animals may be helpful to human health. But they agreed more work is needed to show and measure these facts in a scientific way.
Recent studies have confirmed an animal coming effect. For example, a research at a government laboratory near Washington examined how animals influence blood pressure and heart rote. The study involves 92 students. All were in good health. Each one met with a dog whom they did not know but who was friendly. The students were permitted to touch or hold the dog. The researchers measured the students' blood pressure and heart ram before and during the meeting. The results showed an overall drop in blood pressure and heart rate after the students talked to the dog. The researcher said the same effect often takes place in the animal itself..
Other students have shown that different people react differently to animals. The good effects of pets on physical and mental health may be linked to a person's position within a social; or economic group.
Researchers say they still do not fully understand the physical changes that take place when humans and animals are together, but they say it is clear that animals fill a human need. Animal pets don't reject people because they are sick or disabled. As a result, they may provide the sick or the disabled with a better sense of security.
(30)
A．That more work is necessary for those facts.
B．That animals are helpless to healthy people.
C．That animals can also become friends of humans.
D．That they had a very successful discovery.
第3题
根据下列文章,请回答 46～50 题。
The Joy of Living Alone
More and more Americans are living alone．Some live alone because of divorce or the death of a partner．________(1)According to a recent U．S．census(人口普查)，25 percent of all households in the U．S．are made up of just one person．This is a dramatic change from the extended families of just a couple of generations ago．
The typical person living alone is neither old nor lonely．________ (2)The majority of these people have chosen to live alone．They are responding to decreasing social pressure to get married and have a family．
It's now socially acceptable，even fashionable。to live alone．As people get better jobs and become financially independent，it becomes possible for them to maintain a one。person household．________ (3)However, people who do get married are marrying at a later age and divorcing more often．
The number one reason given by most people for living alone is that they sire ply enjoy doing what they want when they want to do it．“Living alone is a luxury,” says Nina Hagiwara，38．“0nce you do it，you can’t ever go back to living with others．”David C’Debaca，46，agrees．________ (4)Children think that being grown up means being able to do exactly as they please． ________ (5) the chance to discover whether that freedom is as wonderful as it sounds is a chance more and more Americans are taking．
A．There’s more pressure to get married nowadays．
B．The growing number of women with good jobs has done much to increase the number of people living alone．
C．However, even more people are living alone because they have chosen to．
D．It seems that many grown-ups today are realizing that childhood dream．
E．In fact，a quarter of the 23 million single people in the U．S．are under the age of 35．
F．He says，“I like being by myself．”
第 46 题 请选择（1）处最佳答案。
第4题
OPEC to Increase Production
VIENNA (Reuters) OPEC oil exporters agreed to raise output limits on Tuesday but second largest producer Iran, fearing a slump in oil prices, opted out of the deal.
The Organization of the Petroleum Exporting Countries said nine members, excluding Iran, would immediately turn up the taps to 1.45 million barrels daily, or seven percent, easing output curbs made a year ago.
The pact came after heavy pressure from OPEC's biggest customer the United States to ease the price of oil and avert a slowdown in economic growth in the West.
Saudi Oil Minister Ali al--Naimi said he hoped to see the price of North Sea Brent in the range of $20-$25 a barrel.
"This decision was made in the interests of producers and consumers in a prudent way. It will have a positive impact and moderate prices," he said.
Iran, outside the pact, said it would raise production in any case, though not by as much as under the quota it was offered.
Iranian Oil Minister Bijan Zanganeh said he saw room for only one million barrels a day of extra oil. He said Tehran saw no shortage in the market.
"Our differences are on principles, and not only a few barrels," Zanganeh told reporters after the meeting had closed.
"OPEC is not a political organization," he added.
He had complained during the two-day OPEC meeting of "political pressure". OPEC delegates said that was an apparent reference to the United States which launched a diplomatic offensive to get OPEC to raise supplies and lower oil prices on the world market.
In Washington, President Clinton said of extra supply: "In the aggregate it could be sufficient to get production and consumption back in alignment," he said.
Analysts said they expected oil prices, already on the slide from recent highs, falling quickly into the $20-$25 range.
"This will mean extra supply and have a negative impact on oil prices," said Gary Rose of Petroleum Industry Research Associates.
"We're going to see a stock build in the second quarter. I would not be surprised to see Brent at $21-$22.”
Rose said: "The United States was pressing hard for a substantial increase and most in OPEC were in favor of a big increase." Iran has expressed its displeasure at this political.
Non-OPEC Mexico and Norway, having cooperated with OPEC in cutting exports when prices crashed, are shortly expected to announce their own increases.
1. () Iran will raise production at all, but less than it was offered under the quota.
2. () Iranian Oil Minister Bijan Zanganeh said the market could absorb 1.45 million barrels of extra oil a day at present.
3. () President Clinton said the new agreement could bring production back to the same level as consumption.
4. () Industry analysts said that the extra oil could have a positive effect on the oil market.
5.() Non-OPEC oil producers such as Mexico and Norway have been competing fiercely with OPEC for world market over the years.
第5题
Section B
Directions: There are 2 passages in this section. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A, B, C and D. You should decide on the best choice.
Examinations have a longer history in China than in any other country, yet it is today an issue around in which controversy flourishes. At each stage of their school lives children are faced with exams: exams to enter junior middle school, senior middle school, vocational school, colleges and universities. As a result of having constantly to think of these hurdles facing them children find themselves under constant pressure, unable to take time off from studying exam-oriented subjects to relax with friends or to develop other interests. Within school the concentration on exam success leads to the neglect of courses which are not central to the examinations and a method of teaching and learning which emphasizes training the ability to do well in tests but neglects developing the ability to think creatively.
Despite such criticisms the examination system still has its defenders. Without it, they argue, how can we test students' abilities and evaluate the effectiveness of teachers and schools？ They believe that they provide the only objective way of selecting students and reduce the exercise of unfair back-door practices to gain advantage for children on the basis of influence or corruption. Examinations are also felt to offer the impetus to students to master their subject in a way in which they otherwise might not. "While too much anxiety can be a bad thing, a little anxiety can stimulate students to learn better than if left without any test to pass," says Li Jie, a leading advocate of the value of testing. "I can remember things now which give me great pleasure which I doubt I would have learned at the time if I had not had to do so for the examinations."
Which of the following statements about examinations in China is correct？
A．People can make money out of examinations.
B．Only students of today have to take examinations.
C．Students have to learn more about history than about any other subjects.
D．People have different opinions concerning the value of examinations.
第6题
A senior aide to Palestinian President Yasser Ararat termed the truce offer "a lie" and said yesterday a Palestinian "status of self-defence" would continue as long as Israel occupied land in the west Bank and Gaza strip.
US President George W. Bush welcomed Sharon’s statement White House spokesman Ari Fleischer told reporters in Washington on Tuesday. Fleischer added the United States "would welcome a similar statement" from the Palestinians.
Sharon called for a ceasefire at a news conference on Tuesday in which he rejected a total freeze of Jewish settlement activity, part of a plan by a US-led committee for ending lsraeli-Palestinian violence.
"I’propose to our neighbours that we work together to reach an immediate ceasefire and hope the Palestinians will answer the call postively," Sharon said at the news conference."
"This is only a manoeuvre by Sharon’s government aimed at allevating international pressure on Israel, which was condemned for excessive use of force," countered the Arafat aide, Ahmed Abdel-Rahman.
Israeli soldiers came under Palestinian fire in several parts of Gaza late on Tuesday and a roadside bomb exploded or its border with Egypt, which Israel patrols under interim peace deals, the army said. The soldiers returned fire. Israeli- li army spokesman Ron Kitrey said that, under the new guidelines, soldiers would "protect themselves and prevent terror attacks, "but would not initiate any fighting with Palestinians.
he said they would require government approval to enter areas under Palestinian control or carry out reprisal at- tacks, a change from a policy where Defence Minister Binyamin Ben-Eliezer had given field commanders a free hand to launch incursions.
At least 444 Palestinians, 87 lsraelis and 13 Israeli Arabs have been killed since the Palestinian uprising against Israeli occupation erupted in late September after peace talks stalled.
Palestinians say that ______.
A．Israeli Prime Minister is sincere to call for ceasefire
B．Sharon’s appeal to stop ongoing violence is a "lie"
C．they believe this time will soon witness ceasefire
D．they feel relieved America supports ceasefire
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