题目

British Study Tours Using the wonderful railway system, we offer an unusual holiday,sports and study program. Your hotel is a train: eat and sleep on the trainand spend each day in a different part of Britain.Summer School in France   We offersummer school for students between the age of 12 and 16. Live with a Frenchfamily and choose from different activities including horse-riding, footballand swimming. Summer in Australia   We willarrange a program for students. All our courses take place at the college in Sydney. Morning classes are held in Chinese, evening classes on Australian history 大棚种植番茄，在花期必须在棚内放养蜜蜂并进行人工辅助授粉，其目的是（　　） A、加速果实发育B、减少虫害C、增加产量D、保持优良品种