大骨节病是一种以关节软骨变性与坏死为基本病变的地方性骨关节病。
参考答案：对
已知a是整数，3a2+2a+5是一个偶数，则a是（ ）（奇，偶）。
There are countless ________ leaves as if they were a red blanket_______ the ground.
A．fallen; covering
B．falling; covered
C．fallen; covered
D．falling ; covering
