234. 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
n C, D, and E the use of the second it is so imprecise as to be confusing(所有CDE中的it都称的上是前后眼的,或者墙头草式的指带,因为前边有两个可供指带的选择,就搞不清除它到底指的是那个。不要考虑某某方讲的那些指带原则,gmat正确选项一般都会有效的消除这些麻烦,以让句子表达的最清晰—傻瓜型句子