042004300301043d044c04480435 043e043d 04470430030104410442043e__________041c0430030104480443 0432 043e043104490435043604380301044204380438.

042f 04470430030104410442043e 04330443043b044f0301044e 0441 0432 043f043003010440043a0435.

042104420443043404350301043d0442044b 04470430030104410442043e__________043e0431 04430447045104310435 0438 0436043803010437043d0438 0432 0438043d04410442043804420443030104420435 .

041204350301044704350440043e043c 0441043504410442044004300301 0438 ____ 0434044004430442 0435030104450430043b0438 0432 044204350430030104420440.

041404350301043404430448043a0430 043e030104470435043d044c 043b044e0301043104380442 , 043a043e0433043404300301 04340435030104420438 04380433044004300301044e0442 0432 0444044304420431043e0301043b.

某港某日的潮汐资料为：0200，1.0m；0800，4.0m。该日潮高2.0m的潮时为（）。 A: A0450 B: B0442 C: C0432 D: D0421

某港某日的潮汐资料为：0200，1.0m；0800，4.0m。该日潮高2.0m的潮时为（）。 A: 0450 B: 0442 C: 0432 D: 0421

比较C≡C, C=C, C─C, C=C─C=C的键长次序为: C=C─C=C>C─C> C≡C >C=C|C=C─C=C>C─C>C=C>C≡C|C≡C>C=C>C─C>C=C─C=C|C─C>C=C>C=C─C=C>C≡C|C─C>C=C─C=C>C=C>C≡C

下列哪种主链骨架原子排列最能代表两个肽键?() A: Cα—N—Cα—C—Cα—N—Cα—C B: Cα—N—C—C—N—Cα C: C—N—Cα—Cα—C—N D: Cα—C—N—Cα—C—N E: Cα—Cα—C—N—Cα—Cα—C

比较C≡C(Ⅰ),C=C(Ⅱ),C─C(Ⅲ),C=C─C=C(Ⅳ)的键长次序为( )。 A: Ⅰ＞Ⅱ＞Ⅲ＞Ⅳ B: Ⅲ＞Ⅱ＞Ⅳ＞Ⅰ C: Ⅲ＞Ⅳ＞Ⅱ＞Ⅰ D: Ⅳ＞Ⅲ＞Ⅱ＞Ⅰ