下列物质的用途与其化学性质无关的是（ ） A．用熟石灰改良酸性土壤 B．用盐酸除

(2013·甘肃兰州、靖远名校高三模拟)Social practice is an opportunity for students to gain________better understanding of how________society operates.

A．the；the　

B．the；/

C．a；/　

D．the；a

I don’t know when he_____________; when he__________, I’ll tell you.

A．come; will come

B．will come; comes

C．comes; will come

D．will come; comes

对于哥白尼来说，天空中绝对不动的星体是 [ ]

A.月亮

B.地球

C.水星

D.太阳