问题
选择题
There is still a long way to go to work out all the problems the conservation of natural
resources. [ ]
A.concerning
B.concerned
C.to concern
D.concern
答案
答案:A
There is still a long way to go to work out all the problems the conservation of natural
resources. [ ]
A.concerning
B.concerned
C.to concern
D.concern
答案:A