as put forward______ most challenging question for us to answer.—Yes, it really is. I have never heard______ harder one.

Who is the girl ______ is drawing a picture under thattree

There is no doubt ____ the world climate _____ in recent years because of humans activities.

Thechairman thought ________ necessary to invite Professor Smith to speak at themeeting.

下列词语中加点字的读音完全正确的一组是(　　)