Remember to do this in time of H1N1 ---         constantly the windows to let fresh air enter and move around inside, and avoiding the access to the crowds, a necessity everyday. 
#91817
A
open
B
we open
C
opening;
D
to open
推荐题目
 The student did not catch the last bus, _______, it began to rain cats and dogs.
#91796
A
in the flesh
B
at times
C
what’s worse
D
back and forth
—I don’t think the company may offer you a good pay.—__________,I won’t take the job.
#91761
A
That is to say
B
You mean
C
In other words
D
In that case
He doesn’t have interest in cooking.__________, he’s getting tired of it.
#91787
A
On the contrary
B
On the one hand
C
On the other hand
D
On the whole
The professor has written another book ____ of great importance to computer science. 
#91814
A
which I think it is
B
and I think is
C
which I think is
D
when I think is