题目

Marco found the walls of the Summer Palace were covered______gold and silver and the Hall was so large it could easily______6,000 people for dinner. A.with,seated           B.in,seated                C.in,seat                              D.with,be seated 答案：C某人在电车路轨旁与路轨平行的路上骑车行走，他留意到每隔6分钟有一部电车从他后面驶向前面，每隔2分钟有一部电车从对面驶向后面．假设电车和此人行驶的速度都不变（分别为表示），请你根据下面的示意图，求电车每隔几分钟（用表示）从车站开出一部？