1.(2000年上海)__________ she couldn't understand was __________ fewer and fewer
students showed interests in her lessons.
A.What;why B.That;what
C.What;because D.Why;that
简析:选A。因understand为及物动词,因而本题只能用what引导主语从句。why和because引导表语从句的区别在于:because从句强调原因,why从句强调结果。