The gyrfalcon,an Arctic bird of prey, has survived a close brush with extinction; itsnumbers are now five times greater than when the use of DDT wassharply restricted in the early 1970's. .
(A) extinction;its numbers are now five times greater than 对。
(E) extinction, now with numbers five times greaterthan
答案是A,而我选了E A extinction;its numbers are now five times greater than they were句子和句子的比较,才是对的,注意是时态变化了,所以 they were不能省 E 不知道为什么