--- Is Mr. Smith in the office? --- Yes,
题型:选择题
问题:
--- Is Mr. Smith in the office?
--- Yes,_____ he is in charge of the office,he must be there.
A.however
B.since
C.whether
D.for
--- Is Mr. Smith in the office?
--- Yes,_____ he is in charge of the office,he must be there.
A.however
B.since
C.whether
D.for