OG11th----SC107
The physical structure of the human eye enables it to sense light of wavelengyhs up to 0.0005 millimeters;infrared radiation,however,is invisible because its wavelegth---0.1 millimeters---is too long to be registered by the eye.

(A)infrared radiation, however, is invisible because its wavelength---0.1 millimeters---is too long to be registered by the eye

(E)however,infrared radiation has a wavelength---0.1millimeters---that is too long for the eye to register, thus making it invisible

答案是A，但是我不明白OG上对E的解释，我知道E后面的it指代不清，可是为什么that也有问题呢？

OG上说：usinga restrictive clause introduced by that suggests that not all wavelengths of 0.1 millimeters are too long for the eye to register.

我不太明白该解释，还望高人能够指点，谢谢！

however,infrared radiation has a wavelength(---0.1millimeters---)that is too long for the eye to register, thus making it invisible

that引导限定性定从，表示不是所有红外线的波长都不能被眼睛识别，言外之意，还存在可以被眼睛识别的红外线的波长，显然不符合逻辑，应该用非限定性定从表达

其实OG说的很明白了，主要是限定性和非限定的区别，楼主可以查查以前的帖子。