Choose me as your monitor and I p____to help you.
______ exciting sport it is to climb the mountains!
设四面体的六条棱的长分别为1,1,1,1,2和a,且长为a的棱与长为2的棱异面,则a的取值范围是( )
下列有关组成细胞的元素和化合物的叙述,错误的是( )
如图为模拟隔肌运动的示意图.下列相关叙述中,正确的是( )