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举一反三
【单选题】Most shoppers know the feeling. You stand in front of piles of organic produce and wonder what those premium prices are buying you over and above what you get from standard foods. Not a lot nutrition-...
A.
do not use naturally produced fertilisers
B.
produce carbon dioxide when removing weeds
C.
use high doses of weed-killer
D.
use too many resources to qualify for organic status
【单选题】对于双氧水的分解，下列说法正确的是
A.
增大H2O2浓度，可增大单位体积内活化分子百分数，从而使有效碰撞次数增大
B.
使用催化剂反应速率加快是因为正反应速率比逆反应速率快
C.
催化剂不影响活化能但能增大单位体积内活化分子百分数，从而增大反应速率
D.
升高温度能使反应速率增大，主要原因是增大了反应物分子中活化分子的百分数