(OG10-234)E选项

The physical structure of the human eye enables it to sense light of wavelengths up to 0.0005 millimeters;
            infrared radiation, however, is invisible because its wavelength--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

(B)    however, the wavelength of infrared radia­tion--0.1 millimeters--is top long to be registered by the eye making it invisible

(C)    infrared radiation, however, is invisible because its wavelength--0.1 millimeters--is too long for the eye to register it

(D)    however, because the wavelength of infrared radiation is 0.1 millimeters, it is too long for the eye to register and thus invisible

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

E选项中的it指代imprecise，为什么？看了几个帖子也没有发现有人问过E选项的指代问题。多谢了。

正确答案：A

多谢斑竹解答！

对于指代，我一向有一些迷糊和糊涂～

thus making it invisible是用来修饰infrared radiation,而作为主动，infrared radiation makes it invisible中，it将如何指代呢？

像斑竹所说可能是a wavelength of 0.1 millimeters 或者the eye，可是the eye只是用来修饰the wavelength的定语从句的一部分。如何会与上面的it发生关系呢？

难道是说凡是代词出现之前可以与其对应的名词或者代词都可能成为其指代对象么？

麻烦斑竹帮忙解答一下吧！多谢了！