小刚的速度是奶奶的2倍，两个人同时上楼，奶奶上到了3楼，小刚已经上到了几楼？[ ]
A．2楼
B．5楼
C．6楼
答案：B
—What's the matter with your brother?
—He _______ a bad sore throat. [ ]
A. is
B. are
C. has
D. have
如何对传统农业进行改造？
