较老的岩层渐渐风化.The older strata gradually disintegrate.岩层中有证据表明，该地区在15,000年前曾经非常干旱。Contained within the rock strata is evidence that the region was intensely dry 15,000 years ago.这一岩层中有大量燧石.This layer of rock contains a lot o...
Young people and nursing mothers are exempted from charges.未成年人和哺乳期女性免予起诉。His bad eyesight exempted him from military service.他因视力不好而免服兵役.Her illness exempted her from the examination.她因病而免试....