. _______ different kinds of pianos, the workers farther improved their quality.
#97438
A
To produce
B
Being produced
C
Produced
D
Having produced
推荐题目
She likes _______ but she doesn’t like _______ now, because there are too many people in the pool.
#96404
A
swimming; to swim
B
swim; to swim
C
swimming; swimming
D
to swim; swimming
Bats are surprisingly long-lived creatures, some _______ a life span of around 20 years.
#88688
A
had
B
having
C
have
D
to have
Play, often ______ as an activity for younger children, is still important in the social development of teenagers.
#92505
A
to see
B
seeing
C
seen
D
to be seen
