题目内容：

 

1.The student of Class Three have already cleaned their classroom.( 改为否定句)

The student of Class Three ______ cleaned their classroom        .

2. Her grandfather has been dead since2007 .（对画线部分提问）

________ ______ has her grandfather been dead?

3.The film began about 20 minutes ago．You are late．(改为同义句)

The film has ________  ________ for about 20 minutes．You are late.

4.我们应该循环利用塑料袋而不是扔掉它们。(完成译句)

We should reuse plastic bags                 throwing them away.