单项选择题

As more andmore cars are produced and used，so the （）from their exhaust-pipes containsan even larger volume of poisonous gas.

A.exposure
B.distribution
C.expansion
D.emission

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作业成本计算法与传统成本计算法的主要区别是间接费用的分配方法不同。

答案：正确

单项选择题

Scientists have to work hard to keep（）with moderndiscoveries and developments.

A.company
B.track
C.touch
D.pace