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.
Trees a________ (吸收) the carbon dioxide in the air to produce oxygen.
People have harmed nature through a________ (农业), fishing, hunting and tourism.
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.
I feel really g________ (内疚的) because I made some cruel remarks too.