In the market, vegetables are sold by kilogram, I mean, by weight. A. the; 不填B. 不填; 不填C

In the market, vegetables are sold by kilogram, I mean, by weight.
A. the; 不填
B. 不填; 不填
C. the; the
D. 不填；the

(答案→)A. the; 不填B. 不填; 不填C. the; theD. 不填；the解析：选A。介词by表示“以…计”时，若后接单数可数名词，其前要用定冠词，如：by the week 按周，按星期 / by the ton 按吨 / by the yard 按码 / by the meter 按米；若后接抽象名词，则通常不用冠词，如：by volume 按体积 / by weight 按重量。

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