我们通常见到的飞机,都是具有固定的机翼,好像飞鹰伸张着两双翅膀一样。这种飞机必需在特别建筑的跑道上奔跑相当长的距离才能起飞;降落时也必需对准跑道下降,落地后还要在跑道上(?)行相当长的距离才能够停住。跑道两旁和两端的一定距离以内都不可以有比较高的障碍物。因此,一般飞机 The planes we usually see are all fixed wings, as if the eagle spread its wings. This kind of aircraft must run a long distance on the runway of a special building before it can take off; it must also be aligned with the runway to descend when landing, and it should be able to stop for a considerable distance on the runway after landing. Both sides of the runway and both ends of the runway must not have relatively high obstacles. Therefore, the general aircraft