39 In the United States, air pollution _____ at its worst in the 1960s.
(A) being
(B) was
(C) to be
(D) will be

答案：登入後查看
統計： A(58), B(310), C(22), D(15), E(0) #1210416

詳解 (共 1 筆)

#1632410
In the United State...
(共 104 字，隱藏中）
前往觀看
11
0