问题
选择题
We collected a lot of books to get the necessary information but only half _________helpful, so we failed to finish the work.
A．is
B．are
C．was
D．were
答案
答案：D
考查主谓一致.句意:我收集了许多书以获得必要的信息,但是只有一半有帮助,因此我们未能按时完成工作.根据上下文可知谓语动词用过去时态,复数的一半还是复数,故用are的过去时态were,选D.
