We can’t live without________/'wɔ:tər /.

Being able to afford ______ drink would be ______ comfort in those tough times.

A．the; the

B．a; a

C．a; /

D．/; a

--What a clean kitchen!

--Yes, and it _____ by my mother every Saturday.

A. cleans                      B. is cleaned          C. has cleaned

肾小管病变时，尿液中增多的是()

A．鳞状上皮细胞

B．大圆上皮细胞

C．尾形上皮细胞

D．小圆上皮细胞

E．肾小管上皮细胞

什么是径向游隙？

图书馆学是研究图书馆事业的发生、发展、组织形式及其（）的一门科学。