A:塑料笔杆
B:橡胶手套
C:不锈钢尺
D:陶瓷碗
膀胱是形成尿的主要器官。(判断对错)
His eighth book ________earlier this year and was an instant bestseller.
已知AB→=(4,1),BC→=(-1,k)若A,B,C三点共线,则实数k的值为( )
____