They are good friends．It is no _________ that they always help each other．
A.wonderB.doubtC.wayD.idea在线课程A
“It is no wonder that...”是it作形式主语，作真正主语的主语从句置于句子后部，该句意思是“难怪……”，“……并不奇怪或十分自然”，有时该句型中的It's和that也可省略.答案为A.例如：
No wonder(that)he didn't want to go．难怪他不想去.
It's no wonder you can't sleep when you eat so much．
你吃得太饱，自然睡不着.
He has been studying very hard．No wonder that he has passed the examination．他一直努力学习，难怪他考试及格了.