If a computer crashes,you will lose the file you _____ on unless you save it regularly.   
#104026
A
are working
B
work
C
will work
D
worked
推荐题目
Do you still remember the key points that ___________ in his report? I don’t remember them all. 
#102323
A
referred to
B
were referred
C
he was referred to
D
were referred to
If you ________ Beijing Duck,I'd like to treat you to a meal at a famous duck restaurant.
#104939
A
didn't try
B
don't try
C
haven't tried
D
hadn't tried
 Don’t call him at this time tomorrow, because he ________ a meeting with his teachers.
#99910
A
is having
B
is going to have
C
will be having
D
has been having
With the development of high technology, more and more new things ______ in the past years.
#100055
A
discovered
B
have discovered
C
had been discovered
D
have been discovered