1. If A is right about B and III, then pay attention to B and III.

E says the third one is wrong, so E says the second one is right.

What Ding said about B is wrong, so C is right.

Since Ding is right about the second one, pay attention to Ding and the second one.

The fourth point of B is wrong,

3. So C says E is the fourth mistake, then A is the first right, which contradicts the above proof that C is the first.

4. Therefore, the initial judgment is not established. A should say B, the third one is wrong and the third one is right.

6. Because C is the fifth, combined with D, C is the wrong first, then B is the right second.

7. Because B is the second, combining with B, we can see that D is the second mistake, so E is the fourth pair.

8. Because B is the second, combined with E, it can be seen that D is the second mistake, then A is the third pair.

9. To sum up, if you look at C as a test, the fourth of E is right and the first of A is wrong. The investigation fully meets the requirements of the topic.

10. So the ranking is: butyl, ethyl, pentyl, propylene. Check the meaning of the question again, which is exactly what it means. So the second decision is the final answer.

1 1. Extra points! ?

To show that I deserve extra points, I will teach you another secret method: drawing.

When I draw, each row of the grid shows what each of them said, each column shows who they said, and the numbers in the grid show the rankings they said. Then find the next repeated judgment. For example, if two people say that one is the second, I might as well judge that he is wrong, put a cross, and then put a cross in each row according to 1. 2. Each number can only appear in one column. 3. Each column can only have one number. These three principles are used to draw wrong numbers, and when there are contradictions, it means that the initial judgment is wrong.