【问】 He has a lot of books，everyone of which are read through and marked from frontto back.

给的答案要求将are改为is。这无疑是正确的。但我认为试题本身有错误：everyone应改为every one。不知您是否同意我的看法。

【答】 我完全同意你的看法。F. T. Wood在Current English Usage中明确指出：“The com-pound everyone can be used only to refer to people. For things，two words(every one) are nec-essary(复合词everyone只能用于指人，指物时，必须使用两个词every one)：

She bought a dozen eggs，and every one was bad.”(P.101)

(参见everyone/every one¹)