单项选择题
A.Fantastic observanceB.Spiritual practiceC.Individual observance of traditionD.A complex of activities
A.It employs more men.B.It is difficult and dangerous.C.It can save both time and money.D.It means less mechanization.
A.insecticides are not dangerous to any small animalsB.insecticides do not always accomplish their purposesC.insecticides are no longer being used to kill insectsD.insecticides do no harm to people