阅读下面短文，将短文中画线部分的句子翻译成中文
                                                                                How Much Water Is Needed a Day?
   Many people think they should drink eight glasses of water a day．Why? Because that is what they have been told all their life．But a new report on science gives some different suggestions：people should drink according to their bodies．____ They should drink as much water as they would like to drink．
   The report says most people meet their daily needs for water by letting thirst be their guide．It also gives people some good suggestions：women should get about 2.7 liters（升）of water every day，while men should get about 3.7 liters．
   There is an important difference．____ The report doesn’t tell people how many glasses of water to drink．Instead，the experts say it may not be possible to know how many glasses people really need．This is because the daily want of water can include the water in foods．

①对别人的任何批评都要听从  ②努力发掘自己的潜能 
③拿自己的不足比别人的长处  ④善于发现自己的优势，树立自信

已知x₁、x₂是方程x²-3-x=0的两根，则x₁²+x₂²的值是（　　）

如图所示，用滑轮组将重为900N的物体匀速提升2m，下面说法不正确的是（）