题目

Poor weather. Technical difficulties. These are some of the typical causes of cancelled trains and planes. But sometimes, the excuse can be a lot more trivial. Just recently, passengers waiting for a train to Peterborough heard the following announcement, “For reasons beyond our control, we regret to inform passengers that the 13:46 Train to Peterborough has been cancelled. The next train will be arriving on Platform in approximately 36 minutes.” Oh, well, another delayed train, thought most passengers. But a couple of them decided to enquire further. Incredibly, they were informed t青海和西藏的牧场主要是（ ）A.温带草原牧场 B.山地牧场C.高寒牧场 D.河谷牧场