Maintaining this environment is very costly, and recent research shows that even oldoil paint is unaffected by wide fluctuations in temperature and humidity.
维护这样的环境是非常昂贵的，而且最近的研究表明，即使是旧的油画也不会受到温度和湿度大波动的影响。
2
When people pour old motor oil on the ground or throw it in the garbage, it pollutes the environment.
当人们把旧机油倒在地上或扔到垃圾里，它会污染环境。
3
By the time Alexandra was seven years old, she had begun painting with oil paints.