题目内容双击单词支持查询和收藏哦～
收藏
纠错
Statement I. From 1983 to 1991, the yearly level of ultraviolet rays, or UVRs, to which the average person was exposed went down considerably.
Statement II. From 1983 to 1991, the occurrence of retinal irritations caused by UVR exposure went up twofold from previous levels, which were already high. This was true for those people whose exposure was average for each year during the eight-year period.
Which of the following, if true, would reconcile the apparent inconsistency between Statement I and Statement II?
-
A.The retinal irritations caused by UVR are only temporary.
-
B.Atmospheric elements fail to weaken UVRs.
-
C.From 1975 to 1983, the average level of exposure to UVRs also decreased.
-
D.Since 1991, the average level of exposure to UVRs has gone back up to pre-1983 levels.
-
E.The period of time between exposure to UVRs and the incidence of retinal irritations caused by such exposure is usually longer than 8 years.
E显示答案
