链条与链轮装配时要求主动轮与被动轮的轮齿几何中心线应重合，其偏差不应大于两链轮中心距的()。
A. 0.1%
B. 0.2%
C. 0.3%
D. 0.4%
We are busy reviewing our lessons because the final examination is______ .
A. round the corner
B. at the corner
C. in the corner
D. on the corner
To solve the problem of child labor , the writer suggests______ .
A. confining employment of children to small industries and family businesses, looking over factories more closely, and improving the system of education
B. improving laws of protecting children's interests, looking over factories more closely, and punishing lawbreakers with severer fines
C. improving laws of protecting children's interests, giving them lighter work, and raising their payment
D. punishing lawbreakers with severer fines . improving children's working conditions, and confining employment of children to light industries
When a customer finds that his purchase has a fault in it the first thing he should do is
A. write a firm letter of complaint to the store of purchase
B. show some written proof of the purchase to the store
C. complain personally to the manager
D. threaten to take the matter to court
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