________the working efficiency，the boss allows the employees to have a coffee break.
#88719
A
Improving
B
To improve
C
Having improved
D
Improved
推荐题目
His first book ________ next month is based on a true story.
#88711
A
published
B
to be published
C
to publish
D
being published
The old man, ________ abroad for twenty years, is on the way back to his motherland.
#93411
A
to work
B
working
C
to have worked
D
having worked
Blamed for breaking my promise，I felt my face ____ hot，and hung my head in shame.
#90959
A
to grow
B
to be growing
C
grow
D
grown
________in his online games, I am afraid, may lead to his failure in this mid-term exams.
#89790
A
Absorbed
B
Being absorbed
C
Absorbing
D
To absorb