病人是如何感染的
A．异体体外感染B．自体感染C．经皮肤感染D．经血液感染E．经节肢动物传播
参考答案：B
It's no use ____ to persuade him to get rid of that habit; he can't make ____. [ ]
A. trying, it
B. to try; it
C. trying; that
D. to try; that
一只玻璃瓶的质量是200g，装满水时的总质量是700g；装满另一种液体后的总质量为600g，这种液体的密度是多少？
