In what way is salinization a serious problem for agriculture？
A. Soils with high salt concentrations are destructive to crop plants．
B. Salinization can lead to soil compaction or to LOSS of soil cover．
C. Excessive amounts of water are required to prevent salinization．
D. Adding salt to fertilizer raises the operating costs of agriculture．
查看答案
人类掠夺式的开发造成生态环境破坏是生物灭绝和濒危的主要原因。 [ ]
A. 正确
B. 错误
The word abundant in paragraph 3 is closest in meaning to
A. numerous
B. tropical
C. familiar
D. poisonous
A．releasedB．publishedC．announcedD．issuing
A. released
B. published
C. announced
D. issuing
We can learn the meaning of "odor" (Paragraph 2) is ______.
A. smell
B. gas
C. possibility
D. smoke
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