The lack of complete historical records from the mid-to-late 1800's have made some Black inventions difficult to trace to their originators.
(A)have made some Black inventions difficult to trace to their originators.
(B)have made for difficulties in tracing some inventions by Blacksto their originators.
(C)have made it difficult to trace someinventionsby Blacks to their originators.
(D)have made it difficult to trace someinventionsto their Blacks originators.
(E)have made it difficult in tracing someBlacks inventionsto their originators.
答案是D无疑，但是Lily老师在讲的时候强调了主语是The lack，所以谓语动词应该是单数，请问作何解？ 作者: kzang90 时间: 2010-12-15 21:07
Then 蓝皮书 is wrong. It should read as "has made it difficult to trace . . . "作者: dongstar 时间: 2010-12-19 20:54
