1.I don't know when we shall leave for Germany.（改为简单句）
I don't know when (to) (leave ) for Germany.
2.There is almost no meat on the plate.(保持原句意思)
There is (hardly) (any) meat on the plate.
3.I haven't seen her since 1997.（同上）
(The) (last) (time) I saw her was in 1997.
4.I met one of my friends in the street by chance.（同上）
I (happened) (to) meet one of my friends in the street.
5.I was sorry to hear that.（同上）
I was sorry (when) (I) (heard) that.
6.There was only a card on the table.（同上）
There was (nothing) (but) a card on the table.
7.完成对话，每空格限填一词
A:Which book is more interesting?
B:It's (the ) (thicker ) (one ).