有3名打字员为4个科室服务，如果4个科室各有一份文件要打，各科室打字员的选择是随机的，问每个打字员都收到文件的概率
参考答案：
The shopkeeper did not want to sell for ______ he thought was not enough. [ ]
A. where
B. how
C. what
D. which
焦炉煤气的爆炸范围为6％～30％。
