人教版 Book 4(Reading , Speaking & Writing)Using languageVSStep1 Lead-in big and beautifulfresher, healthier, taste better to improve the output of the crops fertilizer herbicide pesticide natural fertilizer from animal wastechemical fertilizerHow many kinds of fertilizers do farmers use? Which kind do farmers use when they are doing organic farming? Chemical fertilizers green food organic food Chemical or Organic Farming?D. Long-term use of chemical fertilizerscan cause damage to the land and peop