（）是传统封闭式基金的交易便利性与开放式基金可赎回性相结合的一种新型基金。

A、A

B、P（A）

C、{ <φ,a> , <φ,b> ,<{a},a>,<{a},b>,<{b},a>,<{b},b>, <a,a> , <a,b> }

D、{ <a,φ> , <b,φ> , <a,{a}> , <b,{a}> , <a,{b}> , <b,{b}> , <a,a> , <b,a> }

下列5个命题，其中正确的个数为（） ①a∈A？a∈A∪B　 ②A？B？A∪B=B　 ③a∈B？a∈A∩B ④A∪B=B？A∩B=A　 ⑤A∪B=B∪C？A=C． A．2 B．3 C．4 D．5

证明：AΔB=(A∪B)\(A∩B)；AΔB=(A∩B^c)∪(B∩A^c)。

A．a=2 b=1 if a>b: a,b=b,a print(a,b)

B．a=2 b=1 if a <b: a,b="b,a">

C．a=2 b=1 if a>b: a,b=b,a print(b,a)

D．a=2 b=1 if a>b: a,b=b,a print(a,b)

A．{ a=b; b=a; }

B．{ b = a * b; a = b / a; b = b / a; }

C．{ t=a; a=b; b=t; }

D．{ a = a + b; b = a – b; a = a – b; }

She has stored ______books as I.

A. three times as many

B. three times as much

C. four time as many

D. three time as much

The computer of the airports have helped people greatly. ______,more people travel by plane in China.

A. In fact

B. At least

C. At one time

D. As a result

—I am not quite myself today.

—______go and see a doctor?

A. Why don't

B. Why not

C. Why you

D. Better to