_____ many times, but he still doesn’t know how to operate the machine properly.
#92970
A
Although I have shown him
B
I have shown him
C
Having been shown
D
Having shown
推荐题目
It was the first time Mary _____ such a big opening ceremony.
#92294
A
has attended
B
attended
C
had attended
D
should attend
___________ was no doubt __________ someone had broken into the store the day before.
#93261
A
There; that
B
There; whether
C
It; that
D
It; whether
Welcome to visit our company whenever ________.
#92279
A
you are convenient
B
you will be convenient
C
it is convenient to you
D
it will be convenient to you
The big fire in Shanghai, believed to ______ due to the burning of construction materials, caused 58 deaths and destroyed all the belongings of the people there.
#92469
A
have occurred
B
occur
C
have been occurring
D
be occurring