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举一反三
【单选题】Mrs. Brown had a small garden behind her house, and in the spring she planted some vegetables in it. She looked after them very carefully, and when summer came they looked very nice. One evening Mrs. ...
A.
Right.
B.
Wrong.
C.
Doesn’t say.
【单选题】毒性的上限指标有
A.
绝对致死量，最大耐受量，最大无作用计量，最小致死量
B.
绝对致死量，最大耐受量，半数致死量，最小致死量
C.
绝对致死量，最大无作用计量，阈计量，半数耐受计量
D.
绝对致死量，阈计量，最大耐受量，最小致死量