翻拍必须使用微距镜头，是因为翻拍原件一般较小（）
参考答案：拍摄距离近
----Volunteering is becoming ______ popular in China.
---- Yeah. People are now aware that helping others is helping themselves.
A．increasingly
B．naturally
C．frequently
D．fluently
隔声窗一般采取（）玻璃。
A．双层或二层
B．三层或四层
C．四层或七层
D．五层或七层
