He was sinking into the Slough of Despond.他那时正陷入极度沮丧的状态。He saved her from the slough of despond.他把她从绝望的深渊中拯救了出来.She could have been trying to encourage a patient who threatened to despond.她像是在鼓励一位眼看就要垂头丧气的病人....
A large proportion of the fluorine is vaporized during the concentration process.在浓缩过程中大部份氟蒸出.health effects of fluorine pollution氟污染对健康的影响If the fluorine content is high, it may increase plant corrosion.如果氟的含量高, 会加剧设备的腐...