宇宙中最基本的天体类型是（）
A.恒星和行星
B.恒星和星云
C.彗星和地球
D.卫星和星云
参考答案：B
He would rather ________for himself than________for a meal.
A．cook；going out
B．to cook；go out
C．cook；go out
D．cooking；going out
The Guangzhou Tower ______ thousands of tourists since it open to the public.[ ]
A. attracts
B. attracted
C. has attracted
