Early this year, thousands of migrant _______ workers cancelled their insurance due to the lack of _______ policy to transfer insurance between difference regions.

A．the; the

B．the; a

C．/; the

D．/; a

下长坡连续使用行车制动会造成什么不良后果？

A．缩短发动机使用寿命

B．驾驶人容易疲劳

C．容易造成机动车倾翻

D．制动器制动效果下降