字时间

Groundbreaking research by two french geophysicists promises to shed some light on the mystery.using 80 metres of deep sea sediment core, they have obtained measurements lots of magneticfield intensity that span 11 polarity reversals and four million years.the analysis reveals that intensity appears to fluctuate with a clear, welldefined rhythm.although the strength of the magnetic field varies irregularly during the short term, there seems to be an inevitable longterm decline preceding each polarity reversal.when the poles flip―a process that takes several hundred thousand years―the magnetic field rapidly regains its strength and the cycle is repeated.

答案为d。这一题目是根据上下文判断词意的题。flip的意思是&快速翻转&，它所在的句子的意思是&当两极互换――这一过程需要上万年的时间――磁场会很快重新恢复它的强度，新的一轮循环又开始了。&因此在四个选项中： a.decline的意思是&拒绝；变小、变弱&，b.intensify的意思是&变得更强烈、加剧&，c.fluctuate的意思是&涨落、波动&；d.reverse的意思是&使反转、倒退、颠倒&，例如：writing is reversed in a mirror。写出来的字在镜子里是颠倒的。d的意思与flip最接近。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。