题干
—Will you go swimming with me this weekend?
—______.
A：All depend
B：It depend
C：It depends o
D：All depends o
答案(点此获取答案解析）
B
A：All depend
B：It depend
C：It depends o
D：All depends o
a、b不共线，e1 =ka－b，e2 =2a+b，若e1// e2，则实数k的值
为 ( )