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【单选题】
下列有关喹诺酮类抗菌药构效关系的那些描述是不正确的A.
N-1位若为脂肪烃基取代时，以乙基或与乙基体积相似的乙烯基、氟乙基抗菌活性最好
B.
2位上引入取代基后活性增加
C.
3位羧基和4位酮基时此类药物与DNA回旋酶结合产生药效必不可缺少的部分
D.
在5位取代基中，以氨基取代最佳。其它基团活性均减少
E.
在7位上引入各种取代基均使活性增加，特别是哌嗪基可使喹诺酮类抗菌谱扩大
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【简答题】A. Rewrite the following sentences after the models, using the structure “there is (no) room for...”. Model 1: There is not enough space for a drive-thru window, or for seating inside. →There is no ro...
【简答题】A. Rewrite the following sentences after the models, using the structure “there is (no) room for...”. Model 1: There is not enough space for a drive-thru window, or for seating inside. There is no roo...
【多选题】物业管理工作自身的特点决定了物业服务合同签订时，除了遵循签订一般合同时的注意事项外，还要注意的要点包括( ).
A.
“宜细不宜粗”的原则
B.
不应有无偿无限期的承诺
C.
实事求是留有余地
D.
保证企业财务管理的总体目标
E.
明确界定违约责任与处理方式
【单选题】There would be more joy in life if we were to accustom ourselves to use all the beautiful colors we can in fashioning our own clothes. The dress of the future will use drapery to a great extent and wi...
A.
it is harder to choose nice dress for men than for women
B.
historical costume was neither beautiful nor appropriate
C.
nobility of dress would help improve the quality of art
D.
the double waistcoats perpetuated in marble are dead
【单选题】He finds it difficult to himself to the climate here．
A.
account
B.
accustom
C.
apply
D.
adopt
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