问题：
Jiaxing is a small city. Therefore, to ______ the flow of traffic, the government has decided to broaden some main streets.
A．speed up
B．build up
C．put up
D．come up
Jiaxing is a small city. Therefore, to ______ the flow of traffic, the government has decided to broaden some main streets.
| A．speed up | B．build up | C．put up | D．come up |
参考答案：