News Plus慢速英语:美国科学家搜索互联网未发现时间旅行者

重点讲解：
1. keep sth. to oneself
把…秘而不宣；不将…说出去；
eg. I have to tell someone. I can't keep it to myself.
我得找人说说。我心里憋不住。
eg. There's one thing you can do for me. But keep it to yourself.
有件事你能帮我做。但你要保密。
2. search for
搜寻；搜索；搜查；寻求；
eg. He searched for work at various stores.
他在各家商店寻找工作。
eg. He who would search for pearls, must dive deep.
采珍珠的人必得潜入深海。
3. believe in
相信有…；认为…存在；
eg. Many African tribes believe in reincarnation.
许多非洲的部落都相信人会转世。
eg. I don't believe in the supernatural.
我不相信超自然现象。