【单选题】The passage suggests which of the following about changes in the earth's magnetic alignment?
A.
They are infrequent events, whose causes are yet to be conclusively established.
B.
They occur infrequently but at regular intervals, more often through the diffusion process than 'field regeneration'.
C.
They occur regularly, more often through the 'field regeneration' process than through diffusion.
D.
They occur frequently but irregularly, because 'field regeneration' is more often the cause.
E.
They occur irregularly, largely because they are dependent on the rare large changes in the flow of the earth's core.
【单选题】听力原文:M: Can I have a single room for tonight, please? W: Sorry, sir. All our rooms are fully occupied. Where does this conversation most probably take place?
【单选题】听力原文:W: I'm sorry, sir. The train is somewhat behind. Take a seat, and I'll tell you as soon as we know something definite. M: Thank you. I'll just sit here and read a magazine in the meantime. What c...
【简答题】侧向推铅球动作时,躯干的转体动作是由 和 在 固定的条件下收缩完成的。
【简答题】侧向推铅球时,躯干的转体动作是由( )和( )在( )固定条件下收缩完成的。
【单选题】下列关于“6”的叙述中,不正确的是( )
【简答题】ISBN 码。 【问题描述】 佳佳的奶牛们喜欢看书,并且佳佳发现在他的奶牛们稍微看了些有关自然科学的书时,会产出更多的牛奶。于是,他决定更新牛棚里的图书馆,把原先廉价的小说换成数学课本。不幸的是,有些新书掉到了泥浆里面,现在它们的ISBN码很难分辨出来了。 ISBN( 国际标准图书编号)是由10位阿拉伯数字组成的编码,用来唯一地标识一本书、前9位阿拉伯数字描述这本书的一些信息,最后一位数字用来验证...
【单选题】听力原文:W: I'm sorry, Sir. The train is somewhat behind schedule. Take a seat and I'll notify you as soon as we know something definite. M: Thank you. I'll just sit here and read a magazine in the meanti...
【单选题】听力原文:M: I'd like to check in, please. W: Awfully sorry, sir. There are no rooms available now. M: But I reserved a room the day before yesterday. W: Sorry. May I have your name? M: Tom White. W: Pleas...
【单选题】听力原文:M: This is the second time you have been late this week, Helen. W: I'm sorry, sir. M: You'll have to do better than that, or I might find it necessary to let you go. W: It won't happen again, I p...
B.
They are teacher and student.
C.
They are employer and employee.