国际上最著名的科技报告是（）
A.PB报告
B.AD报告
C.NASA报告
D.DOE报告
参考答案：A, B, C, D
原子化器
Mary felt sad over the loss of photos she had shot in Australia, _____ that was a memory she especially
treasured. [ ]
A. as
B. which
C. when
D. where
