–She looks very happy. She________have passed the exam.–I guess so. It’s not difficult after all.

填入下面一段文字横线处的语句，最恰当的一句是 （ ）有人曾向希尔伯特请教： 明天最重要的技术是什么这位20世纪科学界的领袖幽默地说：“到月球上去抓苍蝇。” 。希尔伯特在回答为什么时说：“要实现这一目标，意味着我们要解决人类面临的所有物质困难。”今天，人类已经成功地登上了月球。去月球发电、种庄稼，已经像“抓苍蝇”一样实实在在地呈现在我们面前。

He used to be ________ UNICEF worker, but now he is really ________ excellent basketball player.

IsuggestbuyingheraTeddyBearforherbirthday.—_____someoneelsebringsthesamepresent

Where is Peter I can’t find him anywhere.—He went to the library after breakfast and ________ his essay there ever since.