不等式$\left|\begin{array}{cc}1& x-1\\ x& x+4\end{array}\right|$>1的解集是____ ．

世界上水土流失最严重的地区是（  ）

到目前为止，许多自然灾害仍然不能准确地进行____。

阅读理解

    Jenny's apartment building is in the centre of the town. Jenny is very happy there because the building is in a very convenient(便利的)place.

    Across from the building, there's a laundromat(自助洗衣店), a bank, and a post office. Next to the building, there's a drug store and a restaurant, there are two gas stations(加油站).

    There is a lot of noise near Jenny's apartment building, because there are lots of cars on the street, and there are a lot of people walking on the sidewalk all day and all night.

    Jenny isn't very upset(心烦意乱的)about the noise, though. Her building is in the centre of the town. It's a very busy place, but for Jenny, it's a very convenient place to live in.

甲酸和乙醇发生酯化反应后生成的酯，其结构简式为（　　）