杭州：西湖A．长城：北京 B．无锡：太湖影视城 C．杭州：留园 D．青岛：趵突泉

有①空气；②水；③二氧化碳；④硫粉；⑤过氧化氢；⑥石灰水；⑦高锰酸钾完全分解后的剩余物质．其中属于

混合物的是______；属于纯净物的是______；属于化合物的是______；属于单质的是______（填序号）

根据短文内容完成对话:

Boy: Excuse me, __1__ do you __2__ this in __3__?

Girl: Sorry, I don't know. I'm __4__ __5__ __6__ English.

Boy: What can I do?

Girl: You can look it up in a dictionary (字典).

Boy: But I don't have a dictionary. __7__ you __8__ one?

Girl: Yes, I do.

Boy: Can I __9__ it, please?

Girl: Yes, here you are.

Boy: __10__. I see. It's a bookcase in English.

测定淀粉酶活性时试剂中须添加的离子是（）

A.K⁺

B.Na⁺

C.Cl

D.Mg²⁺

E.HCO₃^-

Jim, This is my mother. Mum,          _ is Jim.   [ ]

A. it is

B. that is

C. he is

D. this is

含膳食纤维最多的食物是（）

A.木耳

B.魔芋

C.海带

D.豆渣

E.洋葱