最佳答案:

　　Ⅰ、

　　1、upside fown

　　2、put to good use

　　3、throw away

　　4、bring back

　　5、pull down

　　6、set up

　　7、be made of/from

　　8、build out of

　　9、be good at

　　10、the importance of environmental protection

　　Ⅱ、

　　1112131415CDEAFⅢ、

　　16、The desk is made of wood and metal.

　　17、When the teacher came into the classroom，the students stopped talking.

　　18、It's important to save endangered animals.

　　19、t's a most beautiful city.

　　20、The money will be put to good use to help disabled people.

最佳答案:

　　Ⅰ、

　　1、environmental problem

　　2、take public transportation

　　3、worse an worse

　　4、noise pollution

　　5、cause problems

　　Ⅱ、

　　678910BAAAAⅢ、

　　11、take care of；care for/about

　　12、to turn off the lights

　　13、To recycle books and paper

　　14、turn off the shower

　　15、is not as clean as；used to be