下列不属于太阳系成员的是[ ]
A、星云
B、小行星
C、彗星
D、流星体
答案：A
Professor White has written some short stories, but he is ______known for his plays.(NMET 1998)
A． the best
B．more
C．better
D．the most
与木材的木质部相比，髓心的强度______。
