According to the passage, which of the following words best describes the efforts of the marine biologists working with oysters？
A. Persistent
B. Intermittent
C. Traditional.
D. Fruitless.
查看答案
【B9】
A. almost
B. most
C. mostly
It is______that every one of us should rebuild his world outlook.
A. compulsory
B. pressing
C. complimentary
D. imperative
The waste pipe is blocked; try______it out with hot water, or just call the plumper to do
A. blushing
B. crushing
C. brushing
D. flushing
She was so______in her work that she didn't notice me when I came in the room.
A. suffocated
B. dipped
C. immersed
D. submerged
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