这一带工厂密集,空气质量长期受到关注。Zhè yí dài gōngchǎng mìjí, kōngqì zhìliàng chángqī shòudào guānzhù.Factories are densely concentrated in this area, so air quality has long been a concern.
路口人群密集,请大家注意安全。Lùkǒu rénqún mìjí, qǐng dàjiā zhùyì ānquán.The crowd at the crossing is dense, so please everyone watch your safety.
夜里密集的雨点打在窗户上,吵得我睡不着。Yèlǐ mìjí de yǔdiǎn dǎ zài chuānghu shàng, chǎo de wǒ shuì bu zháo.At night the dense raindrops beat on the window, and the noise kept me from sleeping.