隔热、隔声效果最好的材料是()。
A.岩棉
B.石棉
C.玻璃棉
D.膨胀蛭石
参考答案:D
A cellphone _____ a camera by most young people in China.[ ]
A. is used by
B. used for
C. is used as
D. is used to
试述葡萄无性系选种的方法和程序。