The teacher didn't like ______composition written by the new student because it didn't make

_______ sense.

A． the;a

B．the;/

C．a; t he

D．a;／

留24小时尿标本时加入甲醛的作用是

A．固定尿中有机成分
B．防止尿液中的激素被氧化
C．防止尿液被污染变化
D．保持尿液中的化学成分不变
E．防止尿液改变颜色