问题补充：
单选题Ididn’tunderstand________ledhimtobelateforthreetimeseveryweek.A.what it was thatB.it was where thatC.how it was thatD.why was it
答案：
A解析understand后的宾语从句是由一个强调句型来充当的, 因强调的是主语, 用疑问词what。正常句为：I didn’t understand what led him to be late for three times every week.
