求助各位三道语法题（新东方全真20）谢谢先

睦羽

The human eye retains an image for (a) fraction of a second longer than the image (is) present ,so a (motion) picture gives a rapid succession (after) still picture to still picture.

这到题选D 即after  可是为什么呢？怎么改？

On country (whose) people migrated to America in greater (numbers) than (anoter) contries was Sweden, (with about) a third of their entire population emigrating in the 1800s.

很明显的another错了，可是前面那个numbers怎么回事？不是应该用单数吗？

Medical Interferon, a large hormone-like protein produced buy the cells of all vertebrae animals , came into (useful) when it was discovered that it inerfered with the infection process.

这个题我就更晕糊糊了，哪位大侠能详解一下么？是不是词性错了？大案选的useful

enjoylife517

以下是引用睦羽在2004-6-15 11:12:00的发言：

The human eye retains an image for (a) fraction of a second longer than the image (is) present ,so a (motion) picture gives a rapid succession (after) still picture to still picture.

这到题选D 即after  可是为什么呢？怎么改？

这个题根据句意，应该是用from。。to。。的结构，指静止的图片连续的出现。跟from time to time有点象。

enjoylife517

On country (whose) people migrated to America in greater (numbers) than (anoter) contries was Sweden, (with about) a third of their entire population emigrating in the 1800s.

很明显的another错了，可是前面那个numbers怎么回事？不是应该用单数吗？

这个numbers应该是没有问题，表示很多人，就是a great number of people的简略表述。类似的表达还有a lot of 和lots，等等

enjoylife517

Medical Interferon, a large hormone-like protein produced buy the cells of all vertebrae animals , came into (useful) when it was discovered that it inerfered with the infection process.

这个题我就更晕糊糊了，哪位大侠能详解一下么？是不是词性错了？大案选的useful

对，肯定是useful错了，这里应该用名词形式，而且come into use 用的场合还是挺多的。

enjoylife517

个人认为，这个全真题20还是不要做了，关键是他的考点实在是模糊，跟考试的考点有差别。我觉得以前的真题应该已经足够训练了。重在总结。

睦羽

谢谢版主拉。因为我没有报新东方的课（是还没有开始上，手里面就没有真题资料，网上没有找到可打印的。）