用所给词的其适当形式填空：1.Onhis

问题详情：

用所给词的其适当形式填空：

1. On his ________ (twenty) birthday, he went to the museum with his parents.

went  _________ ( sail ) in Hainan Island last summer.

has already _________ (forget) his English teacher’s name.

are going to take a direct _______ ( fly ) to New York.

r ______ ( pollute)  is one of the biggest problems in the world now.

【回答】

twentieth 2、sailing  3、forgotten 4、flight 5、pollution

知识点：构词法

题型：完成句子