向CuSO4溶液中逐滴加入过量KI溶液，观察到产生白色沉淀，溶液变为棕色．再向反

印刷店进了一批纸，3天用去1/4，照这样计算，这批纸的5/6可以用______．

Woman: I just can't believe this is our last year. College is going by fast.Man: Yeah, we'll have to face the real world soon. So have you figured out what you are going to do after you graduateQuestion: What do we learn from the conversation

A．The two speakers are at a loss what to do.

B．The man is worried about his future.

C．The two speakers are seniors at college.

D．The woman regrets spending her time idly.

下列不属于人体第一道免疫防线的是

A．皮肤

B．黏膜

C．溶菌酶

D．鼻毛

根据物权是否从属于其他权利而存在，可将物权分为______和从物权。

A．主物权
B．抵押权
C．自物权
D．他物权

实际流体流经等截面管路时，若截面1和截面2的位置水头相同，截面2处压力水头小于截面1处，则压力能转化为（）。

A.位能

B.动能

C.热能

D.热能十动能