下列关于泥石流特点的叙述,正确的是( )
A:规模不大,但危害严重
B:活动频繁,历时长
C:危及面狭窄,且重复成灾
D:突发性强,历时短
血浆中含量最多的有机物是水.(判断对错)
用“已经”造句
Only good swimmers can get to that place. There is water all ________ it.