对于一个放行飞到灭有备降机场的岛屿机场的旗机航班，涡轮喷气式飞机必须有足够的油量飞到那个机场，其后还能（）.
参考答案：以正常的巡航耗油量飞至少2小时
热量绝不会由（）处自动流向（）处。
—I’m sorry, but the manager isn’t here yet. Shall I have him call you when he comes back?
—No, I’ll call him later. If I call again in half an hour, do you think he ____?
A．arrives
B．has arrived
C．will arrive
D．will have arrived
