【单选题】What is the connection between farmers and chemicals?
A.
Most farmers do not use chemicals and have no education about their safe use.
B.
Most farmers do not use chemicals and have little education about their safe use.
C.
Most farmers do not use chemicals and have a great deal of education about their safe use.
【简答题】How many chemicals does tobacco contains?
【简答题】当反应中生成的有毒和刺激性气时要用气体吸收装置吸收有害气体。选择吸收剂要根据()来决定。例如,可以用()吸收卤化氢;用()吸收氯和其它酸性气体。
【简答题】A.Farming without using chemicals. B.Farming using machines. C.Farming using chemicals. D.Keeping cows and sheep.
【简答题】内生肌酐清除率的正常值是()-()ml/min