They use computers to keep the traffic         smoothly.  
#98965
A
being run
B
run
C
to run
D
running
推荐题目
______ another button and your meal is prepared and heated for you.
#97696
A
If you press
B
To press
C
Press
D
Pressing
—Is the boy your own son?—No. He is an _____ child _____ himself Martin.
#94503
A
adopted, calling
B
adopted, called
C
adopting, calling
D
adopting, called