不属于军事基础高技术的是（）。
A.电子技术
B.新材料技术
C.纳米技术
D.动力技术
参考答案：C
已知函数y=-3x+b的图象过点（1，-2）和（a，-4），则a=______．
-Hey, guys. Do you often have a good time ________ after-school activities?
-Of course, we do. And we always have a lot of time ________ soccer.[ ]
A. to do; to practice
B. doing; practicing
C. to do; practicing
D. doing; to practice
