单选题 The magician picked out several persons ______ from the audience and asked them to help him with the performance.
A. by accident B. on average C. on occasion D. at random

【正确答案】 D
【答案解析】[解析] D项“at random随意的”符合题意。其他三项“A项by accident偶然的；B项on average平均的；C项on occasion有时”都不正确。本题空格处是说魔术师从观众中随意选了几人。因此D项为正确答案。