________ many times，I still didn't know how to operate the machine.
#91844
A
Having taught
B
Having been taught
C
Being taught
D
Teaching
推荐题目
If you think that treating a woman well means always ________ her permission for things, think again.
#88811
A
getting
B
gets
C
got
D
to get
(2013·天津新华中学二次月考)________ several times，he still couldn't understand how to operate the machine.
#89556
A
Telling
B
Having told
C
To be told
D
Having been told
While crossing the street, you must _______ your riding speed.
#95747
A
just
B
adjust
C
be adjust
D
adjusting
——_________ abroad for 10 years, he went back home.
#96758
A
Working
B
Having worked
C
To work
D
Worked