GoingtothetheaterisverypopularinViennaandtickets

问题详情：

Going to the theater is very popular in <?xml:namespace prefix = st1 />Vienna and tickets ______ far in advance.

A. often sold out          B. are often selling out   C. are often sold out      D. often sell out

【回答】

知识点：一般现在时及其被动式

题型：选择题