Peter was pretty much fine until 2007, when the glaucoma and macular degeneration that had been under control for years suddenly turned catastrophically worse.
Peter的身体状况一直不错，直到2007年他的青光眼和黄斑变性突然变得严重了。
2
The communities of these sand dune-fixed plants suffer severe degeneration and thus need enhanced protection, grazing control and prevention of sand dunes from becoming mobile.
固定沙丘植物群落退化严重，需要加强保护，控制放牧强度，防止沙丘活化。
3
There were many factors contributing to the grassland degeneration, but some were artificial control and others were not.