—How long do you think it is ________ he arrived here?    —No more than half a year, I believe.    
#104908
A
when
B
that
C
before
D
since
推荐题目
We are confident that the environment ________ by our further efforts to reduce pollution.
#100189
A
improves
B
will be improved
C
has improved
D
was improved
-Why can’t I smoke here? --At no time__________ in the dormitory.
#102579
A
is smoking permitted
B
smoking is permitted
C
smoking is allowed
D
does smoking permit
Miriam arrived at 5 pm, but Mr. Whitker _______ the store.
#99789
A
closed
B
has closed
C
had closed
D
was closed