F系列可编程序控制器用( )表示。
A.X
B.Y
C.T
D.C
参考答案:D
He told us he _____ a concert _____ .
A.had attended ... three days before
B.attended ... three days ago
C.would attend ... since three days
D.was attending ... for three days
Near the church _____ cottage. [ ]
A. was such an old
B. had a so old
C. was such old a
D. is so an old