轮状病毒感染后主要侵犯（）
A.十二指肠
B.回肠
C.升结肠
D.空肠
E.乙状结肠
参考答案：D
John and Peter like to __________ their life.
A．talk
B．talk to
C．talk with
D．talk about
若a+b=4，则a2+2ab+b2的值是（ ）
A．8
B．16
C．2
D．4
