题目

The city of Cannes is situated in the southern part of France, in the Riviera region and has a population of nearly 70,000. Cannes is very famous around the world for its Film Festival and also for its Cannes Lions Festival. It is a comfortable city and has tourism (旅游业) as its main industry. Cannes offers some of France's finest hotels. You can surf the Internet for more information about hotels.    It is 905 km away from Paris, 164 km from Marseille and 26 km away from Nice. The coast is often visited. The Boulevard de la Croisette is one of the most important attractions for peo在前进的车厢的坚直后壁上放一个物体, 物体与壁间的静摩擦因数为μ=0.8,要使物体不致下滑, 车厢至少应以多大的加速度前进, 如图[    ] A.a≥g／μ　　B.a＞g／μ C.a＜g／μ　　D.无法判断