噪音防护的途径有（）。
A.声源上降低噪声；
B.传递途径上降低噪声；
C.个体防护；
D.没有办法防护
参考答案：A, B, C
The picture in the advertisement showed an attractive actress playing _____, with her
blouse hanging loosely to the floor. [ ]
A. a musical instrument
B. a musical equipment
C. musical instruments
D. musical instrument
动物细胞的细胞质中含有叶绿体，所以能进行光合作用合成有机物．______．
