A:72°
B:60°
C:58°
D:50°
如图,三角形ABC中,∠C=90°,AC=3,点P是BC边上一动点,则AP的长不可能是( )
现有一瓶某品牌的饮用纯净水,用手握住水瓶在空中静止不动,此时水瓶受到的重力和手对瓶的____ 力是一对平衡力;若在松开手的瞬间,水瓶所受的所有力都突然消失,水瓶将____ ;若将水瓶抛向上空,水瓶能够继续向上运动,是由于它有____ .
下列哪种状态,肺内气体出肺( )
—You must be very excited about going to England for further study.— , but I am afraid I won't do well because my English is poor.
青藏高原地区农作物分布在河谷地带的主要原因是( )