我校今年栽的树的成活率为99%,只有2棵树没有成活,栽的树共有200棵.______.
2÷(1-99%),
=2÷1%,
=200(棵);
总棵数是200棵.
故答案为:√.
-- Is Mr Smith really very ill? --________. He's in hospital.
A.I don't think so
B.No, he isn't
C.I hope so
D.I'm afraid so
氨氮检测所需要得蒸馏仪器包括()。
A、凯氏烧瓶
B、型冷凝管
C、氮球
D、导管