设随机变量X的数学期望E（X)=μ，方差D（X)=σ2，则由切比雪夫不等式有P（X-μ|≥2σ)≤______．

r I tr________, I could not memorize the text.However hrd did I try B．However hrd I tried C．However I tried hrd D．However I hd tried hrd

A．However hard did I try

B．However hard I tried

C．However I tried har

D．However I had tried hard

D．HoweI could not remember the text .However hrd did I try B．However hrd I tried C．However I tried D．However hd I tried hrd

A．However hard did I try

B．However hard I tried

C．However I trie

D．However had I tried hard

听力原文：W: Mr. Brown, I tried to memorize the script. but I keep forgetting the lines.

M: Look, Mary, you'll be fine if you stop putting so much pressure on yourself.

What's the man's attitude towards the woman？

A．Mary is not so forgetful.

B．Mary used to have good memory.

C．Mary shouldn't be so nervous.

D．Mary shouldn't try to memorize the whole script.

I could not persuade him to accept it, _____ the important of it.

(A) if only I could not (B) no more than I could (C) or I could not (D) nor could I

听力原文：W: Mr. Brown, I tried to memorize the script. but I keep forgetting the lines.

M: Look, Cathy, you'll be fine if you stop putting so much pressure on yourself.

Q: What does the man mean？

(18)

A．Cathy is not so forgetful.

B．Cathy used to have a good memory.

C．Cathy should not try to memorize the whole script.

D．Cathy shouldn't be so nervous.

—It is reported tht it will rin hrd next Sundy. — . We’re plnning to go boting tht dy. I don’t think so B．I hope so C．I’mfrid not D．I hope not

A．I don’t think so

B．I hope so

C．I’m afraid not

D．I hope not