[求助] Prep 1-95

Prep1-95：

95.        (29661-!-item-!-188;#058&003962)

Unlike frogs that metamorphose from tadpoles into adults within a one-year period, it takes three to four years for the mountain yellow-legged frog of the Sierra Nevada to reach adulthood, and so they are restricted to deeper bodies of water that do not dry up in summer or freeze solid in winter.

(A) it takes three to four years for the mountain yellow-legged frog of the Sierra Nevada to reach adulthood, and so they are

(B) it takes the mountain yellow-legged frog of the Sierra Nevada three to four years until it reaches adulthood, and therefore it is

(C) in the Sierra Nevada, mountain yellow-legged tree frogs take three to four years to reach adulthood, thus being

(D) mountain yellow-legged frogs of the Sierra Nevada take three to four years until they reach adulthood, thus

and so 和 and是一样的。一般来说and会比and so好，但是一上来就可以确定只有DE 正确，d中的thus又是明显不对的~

thus是副词，如果用thus，restricted to离要修饰的frog太远了。外加，前面两位的Input，and so=and