选用所给的词并用适当的形式完成句子。

surprise  since   she   angry   sweep  heavy      

小题1:__________ we friends, we should help each other as often as possible.

小题2:The more junk food you eat, the ______ you will be .

小题3:To our __________, he won the first prize.

小题4:My mother shouted __________ at me, “Go to bed and don’t watch TV.”

小题5:I am so busy now that I have to put off _________ the floor.

小题6:Lucy was so happy, because she met a friend of ___________. They have not seen for a long time.

什么叫油水边界？