They________ have told me about it yesterday.
问题描述：
They________ have told me about it yesterday.
答
do
They do have told me about it yesterday.
答
should
should have done sth意思是本该做某事（而实际上并没有做）
同样should not have done意为本不该做
这句话意思是他们本该昨天告诉我的（其实昨天没告诉我）
答
A.that B.which C.when D.on which A It be that是强调句型，这里强调时间“昨天” A.that 强调句型
答
already
他们昨到天（已经）告诉我这件事.
答
should