A:充分不必要条件
B:必要不充分条件
C:充要条件
D:既不充分也不必要条件
—Did you have a good time?
—It couldn't be worse. We were held up on the expressway for three hours. On the way back, we found the car got a f____ tyre, and the spare was, too.
如图所示,根据磁感线方向标出电源的“+”、“﹣”极和小磁针的N极.
①它如今散落着的地雷碎片阻挡着孩子们奔跑的脚步。(缩句)
②轰隆隆的坦克和大炮打破了它们的梦幻。(缩句)
③我要向爸爸献上一束最美丽的鲜花,因为他是保卫世界和平的光荣战士。(换个说法,意思不变)
④我的爸爸精通四国英语。(修改病句)
⑤散落着的地雷碎片不能阻挡孩子们奔跑的脚步。(改为反问句)
下列哪个政权灭掉了北宋政权( )