【单选题】比较取代羧酸 FCH 2 COOH(I) , ClCH 2 COOH(II) , BrCH 2 COOH(III) , ICH 2 COOH(IV) 的酸性大小是
【单选题】What is Tian Yuan's mother's advice on dealing with her problem with Lily?
A.
She believes that Lily will feel sorry for her behavior.
B.
She wants to meet Lily and say sorry for Tian Yuan.
C.
She wants Tian Yuan to apologize to Lily.
【单选题】What is Tian Yuan's mother's advice on dealing with her problem with Lily?
A.
She wants Tian Yuan to apologize to Lily.
B.
She believes that Lily will feel sorry for her behavior.
C.
She wants to meet Lily and say sorry for Tian Yuan.
【单选题】比较取代羧酸 (I) α- 氯代苯乙酸, (II) 对氯苯乙酸, (III) 苯乙酸, (IV) β- 苯丙酸的酸性大小是( )
【单选题】比较取代羧酸FCH 2 COOH,ClCH 2 COOH,BrCH 2 COOH,ICH 2 COOH的酸性最大的是()
【单选题】关于进口押汇错误的是()。
A.
我行为进口商先行支付进口货款,使进口商不占压资金即可完成国内货物的加工销售、便利进口商的资金周转
B.
进口商可以在先不支付货款的条件下取得物权单据,提货、转卖或加工销售,从而抢占市场先机
C.
进口商在汇率波动的情况下可申请人民币融资,在进口货物销售前办理购汇,规避汇率风险
D.
变商业信用为银行信用,银行的介入可以使贸易本身更有保证
【简答题】在折射率n 3 =1.52的照相机镜头表面涂有一层折射率n 2 =1.38的MgF 2 增透膜,若此仅适用于波长λ=550nm的光,则此膜的最小厚度为多少?