各位好，有几个句子订正的问题想请教：
1.Except for the phonograph, the accomplishments of distinguished
musicians and the voices of legendary individuals would have been forgotten
by history.
Except for 是错误的，请问是改成Except吗?WHY?
2.Improvements in people’s health are due in part to advances in
medical care and better sanitary.
sanitary是错误的，请问该怎么改?
3.Having been experienced many realistic disaster drills in his
training, Roberts handled the disaster calmly and effectively.
Having been experienced是错误的，请问该怎么改?
4.Compared to those of animals, the fossil record for plants in quite sketchy.
those是错误的，请问该怎么改?
谢谢大家的帮忙~^^