grotto

We reached a beautiful grotto, whose entrance was almost hiden by the vine.

我了一个美洞穴,洞几乎被藤蔓遮掩著。

The particulates have more acidic pollutants with strong acidity and have the corrodibility to grottoes.

细粒子中有较多酸性污染物并比粗粒子酸性强,这些细粒子对石窟有侵蚀作用。

The development of technology and improvement of test methods are the hopes for solving the periodization of grottoes.

科学技术发展、科学测定方法步和完善，是解决石窟分期问题希望所在。