——Excuse me. Do you have a table for ten?——I'm sorry, ______we have a table for eight.
A:but
B:and
C:or
D:so
已知向量a→=(4,x),b→=(2,4),若a→=2b→,则x=( )
—Well, it doesn't keep me awake in the night, I see no harm in it.
世界上长度最长的河流是( )