160×38=60（千克）．
答：梨树有60千克．
— Are you ready for Spain?
— Yes. 1 want the girls to experience that______they are young.
A．while
B．until
C．if
D．before
去氧肾上腺素红外吸收光谱中产生特征吸收峰的波数为酚羟基（vc-o）（）
A．3600～2300cm-1
B．1600,1470cm-1
C．1250cm-1
D．1083cm-1
E．750cm-1
