水域主要污染指标包括
A. 细菌卫生学指标
B. 生物需氧量
C. 固体悬浮物
D. 化学需氧量
Edison said, "Never give up, you will make it ".
A. yet
B. or
C. and
D. but
Lucy and Lily are twins. Lucy likes playing table tnnis, Lily doesn't .
A. or
B. but
C. and
D. yet
There is no airwater on tne moon .
A. and
B. or
C. so
D. yet