Because of various reasons, this new work develops slowly in our country, and there are many problems existed in the practice.
但由于多方面的原因，这项新工作在我国发展缓慢，实践中还存在很多问题。
Result indicates that there are many problems existed in management system and anaerobic digestion technique etc of municipal refuse.
结果表明，在城市垃圾的管理体制和厌氧消化技术等方面都存在很多问题。
The use of these types of chemicals has only added to the environmental problems that have existed for many years.
然而，使用这些具有毒性的化学药物治标不治本，并会带来更多难以解决的环境问题。
应用推荐