削弱相权是中国古代加强皇权专制的重要手段。下列各项中,属于宋朝削弱相权的重要措施是( )
①增设参知政事 ②设立枢密使 ③设立三司使 ④设置刺史
A:①②
B:①③
C:①②③
D:②③④
Drivers must _________ seat belts while their cars are running on the road.