水泥的化学性质指标有:( )
A.氧化镁的含量
B.不溶物
C.烧失量
D.有害成分
参考答案:A,B,C
Many buildings in the city need repairing, but the one first is the library.
A.repaired
B.being repaired
C.repairing
D.to be repaired
淀粉是在哪个消化道开始被消化的
A.口腔
B.胃
C.小肠
D.大肠