在岩巷掘进工作面干久的人,易患的尘肺病是()。
A、煤肺病
B、矽肺病
C、煤矽肺病
参考答案:B
(2014·东北三校模拟)We had just covered half the journey________the engine failed and we could do nothing but wait for help.
A.before
B.since
C.when
D.until
CH4、CH5、CH6、CH7所指示的天气意义是什么?