语法填空

   There are two sets of Games-the Winter and the Summer Olympics, and 1__________ are held every

four years on a regular basis. The Winter Olympics are usually held two year 2________ the Summer

Games. Only athletes 3______________ have reached the agreed standard for their event

4(admit)________________ as competitors. They may come from 5___________ in the world.

     There are no running races 6___________ horse riding events. 7______________ there are

competitions like skiing and ice skating 8______________ need snow and ice. That's 9_________

they're called the Winter Olympics. It's in the Summer Olympics 10____________you have the running

races, together with swimming, sailing and all the team sports.

推料板向前推烟料时对烟料有一个推动作用，而向后拉开时则没有推进，两个过程烟料前进的速度不一样，当推料板摆幅大、（）低时，其作用更明显。