红军战士能够飞夺泸定桥的主要原因是_____。( )
A:红军战士有不畏艰险、勇往直前的精神
B:敌人战斗力不强
C:红军战士跑得快
He lost his key. It made him ________ in the cold to wait for his wife's return.
—Hello! This is David. Can I speak to Tom? —Yes, ___________.
下列材料中符合大功率、远距离输送电能要求并最具有应用前景的是()