Hundreds of years ago, life was harder than it is today. People didn’t have modern machines. There was no modern medicine, either. Life today has brought new problems. One of the biggest is pollu
A teenage girl couldn’t stand（忍受）her family rules, so she left home.She wanted to be a star and became famous. But she had a little education and 41 years later, she had to ask fo
-----I prefer shutting myself in and listening to music all day on Sundays. ------ That’s _____ I don’t agree. You should have a more active life. A. where B. how
（1分）,解得k=－2.（2分）
（3分） 
,这时△= －7＜0 .（4分）
与y = 
+1无交点..（6分）解析: