(用所给单词填空) It took me two hours ______ (reach) Beijing．

(用所给单词正确形式填空) It is hard ______ (understand) how large the universe is．

(用所给单词正确形式填空) 桯as your sister finished her homework?

　　梇es，she ______ just ______ (finish) it．

(用所给单词正确形式填空) 桯ave you seen the film before?

　　桸o，I _______ (not see) the film yet．

(用所给单词正确形式填空) There are more than _______ (billion) of stars in our galaxy，called the Milky Way，and our Sun is only one of them．

(用所给单词正确形式填空) 梂here shall we meet?

　　Let's meet at the (enter) _______ to the cinema．

(用所给单词正确形式填空) No one has discovered any life in space _____ (already)．

(按要求完成句子变化) I have already finished my homework．(改为一般疑问句)

　　______ ______ finished ______ homework ______?

(按要求完成句子变化) They have ever spoken to some foreigners．(改为否定句)

　　They ______ ______ spoken to ______ ______．

(用所给单词适当形式填空) _____ you ______ (finish) your homework yet?

　　Yes， I ______． I ______ just ______ (finish) it．