——David has made great progress recently.——______, and ______.
A:So he has; so you have
B:So he has; so have you
C:So has he; so have you
D:So has he; so you have
下列各选项中,语言表达没有错误的一项是( )
下列各式中,去括号或添括号正确的是( )
已知集合A={x|x≤2,x∈R},B={x|x≥a,x∈R},且A⊂B,则实数a的取值范围是( )