单项选择题
细胞色素C是一种由104个氨基酸构成的蛋白质。分别测定兔、蛇、龟、鲸和马五种动物细胞色素C的氨基酸序列，发现了马与其他动物的氨基酸差异个数（见下表）。
据此推测，四种动物中与马亲缘关系最近和最远的分别是 （ ）
动物
兔
蛇
龟
鲸
氨基酸差异个数
6
22
11
5
A．蛇和鲸
B．兔和鲸
C．鲸和蛇
D．鲸和龟
- A.蛇和鲸
B.兔和鲸
C.鲸和蛇
D.鲸和龟
点击查看答案
相关考题
-
单项选择题
运用转基因技术培养的单细胞“工程硅藻”，可把光合作用合成的有机物以脂质形式储存起来。科学家计划在海水中大量培养“工程硅藻”，捕捞后从中提炼“生物柴油”。与矿物柴油相比，使用这种“生物柴油”的优点是 （ ）①可再生 ②不显著增加碳排放 ③不排放含硫废气 ④不会对生态环境造成负面影响A．①②③ B．①③④ C．①②④D．②③④
A.①②③
B.①③④
C.①②④
D．②③④ -
单项选择题
34 with Father’s Day around the corner, I have taken some money out of the bank—— presents for my dad A buy B.to buyC buying D to have bought
A.to
-
单项选择题
第二节完形填空 阅读下面短文，从短文后各题所给的四个选项(A、B、C和D)中，选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。It was a busy morning，about 8:30,when an elderly gentleman in his 80s came to the hospital .I heard him saying to the nurse that he was in a hurry for all appointment(约会)at 9:30 The nurse had him take a 36 in the waiting area, 37 him it would be at least 40 Minutes 38 someone would be able to see him I saw him 39 his watch and decided， since I was 40 busy—my patient didn’t 41 at the appointed hour, I would examine his wound .While taking care of his wound．I asked him if he had another doctor’s appointment The gentleman said no and told me that he 42 to go to the nursing home to eat breakfast with his 43 .He told me that she had been 44 for a while and that she had a special disease I asked if she would b e 45 if he was a bit late. He replied that she 46 knew who he was，that she had not been able t0 47 him for five years now. I was 48 , and asked him，“And you 49 go every morning，even though she doesn’t know who you are?” He smiled and said．“She doesn’t know me but I know who she is” I had to hold back 50 as he left. Now I 51 that in marriages，true love is 52 of all that is The happiest people don’t 53 have the best of everything；they just 54 the best of everything they have 55 isn’t about how to live through the storm，but how to dance in the rain.36 A breath B.test C seat D break
A.I
B.While
C.I
D.He
E.“She
F.
36
G.test
