填空题

Urban haze, the scattering or absorption of light, is caused by fine particles.

【参考答案】

Y

<上一题目录下一题>

热门试题

填空题

Photochemical smog is formed on rainy days when chemicals are combined with smoke.

填空题

Poisonous particles, such as lead compounds, are cumulative and can build up slowly in the body.