I will visit Austria the invitation of my friend this summer vacation.
A. by
B. for
C. to
D. at
网友回答
A. by
B. for
C. to
(答案→)D. at
解析:固定搭配。At the invition of sb在...邀请下.句意:今年暑假,在我朋友的邀请下我会访问奥地利。For ,prep.为,为了;倾向于;关于;当作 to,.向,往,给。..,于。..,直到。..为止,在。..之前,比,对,[表示程度、范围] 到,达。