See the flags on top of the building ? That was we did this morning.
A.when B.which C.where D.what
解析:
D.本题考查名词从句作表语。根据名词从句的基本特点,该句中的动词谓语did须有宾语,又表示笼统意义,故选what,表示“所…的”。
Tom would visit us tonight, and that’s ________ he was calling about.
A. why B. it C. what D. that