It was several years I had an opportunity of seeing the bird again .A. for; beforeB. not

问题补充：

It was several years I had an opportunity of seeing the bird again .

A. for; before

B. not for ; that

C. for ; when

D. not for ; then

答案：

A. for; before

(答案→)B. not for ; that

C. for ; when

D. not for ; then

解析：可联系答.案.网客服索取。