成人骨骼总数是
A.181块B.215块C.206块D.236块E.221块
参考答案:C
解析:成人骨约206块,包括躯干骨 51块,颅骨29块,上肢骨64块,下肢骨 62块。
设f(x+2)=2x+3,则f(x)=( )
The number of chairs in the room_____ten.I’m afraid a number of chairs in the room____lost.
A.is;is
B.is ;are
C.are;is
D.are;are