已知二元一次方程2x﹣y=1，用y的代数式表示x为（　　）

如果方程（k-2） -3kx-1=0是一元二次方程，那么k的值不可能是（      ）

新浪网2011年6月15日消息从6月10日零时至6时，湖南省临湘市詹桥镇原贺畈乡降下了275.6毫米的雨水。超过上半年降雨总量的特大暴雨，引发了山洪泥石流，将原贺畈乡的观山村、云山村等村组夷为平地。灾害导致20人死亡、8人失踪。为了获得更加及时、准确的灾区的信息，一架小型无人遥感飞机飞临原贺畈乡上空进行遥感拍摄。回答下列问题。

   Volunteering means that you work to help people without being paid. There are many different volunteers. They help people who really need help. There are many places where you can be volunteers. Here are just a few places for you.
   Hospital---ask if you can go and visit people who are really sick. Sometimes what they need is someone to talk to, or someone to give them hope.
   Orphanage (孤儿院) ---the children living there really need someone to play with them.
   Food Shelter---many food shelters need people to clean up the shelters and help give out food or water to those who need it.
Home for the elderly ---help the elderly people clean up their homes.
   Community (社区) Center ---a lot of community centers are very well run. However, some of them really need extra help, especially cleaning and repairs.
   As a student you can also do a lot of things to help others at school. Maybe you could start a support group.
   Here is some advice:
   Help students give up smoking, drinking or other bad habits.
   Help students who come from poor families.
   Help new students get used to their school life soon.
   Provide seniors with information on future studies.