【小题1】It is our d________ (责任，义务) to try to cut back on production and reduce the amount of things we make and buy.
【小题2】Trees a________ (吸收) the carbon dioxide in the air to produce oxygen.
【小题3】People have harmed nature through a________ (农业), fishing, hunting and tourism.
【小题4】Many countries have hesitated to give p________ (准许，许可) for the production of GM foods, as they would rather be cautious with this new technology.
【小题5】I feel really g________ (内疚的) because I made some cruel remarks too.

Don't _____ the news to the public until we give you the go-ahead (许可，准许).

   A. release    B. discard    C. relieve    D. retain

. Don't _____ the news to the public until we give you the go-ahead (许可，准许).

Don't _____ the news to the public until we give you the go-ahead (许可，准许).

　　A. release    B. discard    C. relieve    D. retain

Don't _____ the news to the public until we give you the go-ahead (许可，准许).

   A. release    B. discard    C. relieve    D. retain