分数的倒数一定比原数小______.(判断对错)
34的倒数为43,34<43,
故分数的倒数一定比原数小是错误的.
故答案为:错误.
— Is your mother a bus driver?
— Well, she _______________, but now she is a shopkeeper.
A.used to
B.used to be
C.use to be
D.is used to being
关于药物水解反应的正确表述
A、水解反应大部分符合一级动力学规律
B、一级水解速度常数K=0.693/t0.9
C、水解反应速度与介质的pH有关
D、酯类、烯醇类药物易发生水解反应
E、水解反应与溶剂的极性无关