—Why do you look so puzzled?—Oh，I ________ over a most difficult maths problem.
#99720
A
thought
B
have thought
C
am thinking
D
think
推荐题目
---- How is the old man now? ---- Sorry, he ______ though they did all they could to save him.
#104107
A
was dead
B
had died
C
has been dead
D
died
I won’t tell the student the answer to the math problem until he ______ on it for more than an hour.
#104700
A
has been working
B
will have worked
C
will have been working
D
had worked
-----Oh, you said you’d tell me the latest news about environmental situations. -----Sorry, I_______with my work at hand. I______to that.
#104827
A
deal; will come
B
was dealing; come
C
have dealth; have come
D
have been dealing; am coming
Car rental agencies _______ a boom in business ever since new restrictions made it harder for people to buy an automobile in the capital.
#100686
A
has enjoyed
B
have been enjoying
C
are enjoying
D
enjoyed
Bob ________ with us together since he came to our school.
#101237
A
have worked
B
has worked
C
worked
D
will work