Reordering of sentences (public health and education): arrange P, Q, R and S to form a coherent paragraph between S1 and S6. S1: We do not know, after sixty years of education, how to protect ourselves against epidemics like cholera and plague. S6: This is the disastrous result of the system under which we are educated.

Introduction / Context:
This jumbled passage deals with the failure of an education system to equip people with practical health knowledge. You are asked to order the middle sentences P, Q, R and S between S1 and S6 so that the resulting paragraph is logically and thematically coherent. The key is to trace the author's argument from general criticism to specific examples and then to a suggested reason.

Given Data / Assumptions:

• S1: We do not know, after sixty years of education, how to protect ourselves against epidemics like cholera and plague.
• S6: This is the disastrous result of the system under which we are educated.
• P: If our doctors could have started learning medicine at an earlier age, they would not make such a poor show as they do.
• Q: I have seen hundreds of homes. I cannot say that I have found any evidence in them of knowledge of hygiene.
• R: I consider it a very serious blot on the state of our education that our doctors have not found it possible to eradicate these diseases.
• S: I have the greatest doubt whether our graduates know what one should do in case one is bitten by a snake.

Concept / Approach:
The structure of the argument is:

• General criticism of education regarding epidemics.
• Specific criticism related to doctors and their failure.
• Examples showing the ignorance of ordinary educated people at home.
• A specific doubt about graduates in an emergency situation.
• Conclusion blaming the education system.

We must place sentences so that each idea flows into the next naturally, with R following S1 as it directly elaborates the \"blot\" on education.

Step-by-Step Solution:
Step 1: From S1, the author moves naturally to R, which explicitly mentions \"a very serious blot on the state of our education\" and directly continues the criticism begun in S1. Step 2: After blaming doctors in R, the author widens the criticism to ordinary homes. Q does this by saying there is no evidence of knowledge of hygiene in hundreds of homes visited. Step 3: S continues this line of thought with a specific example: even graduates may not know what to do if someone is bitten by a snake. This deepens the criticism of practical ignorance. Step 4: Finally, P offers a reason and a possible solution by suggesting that if doctors had started learning medicine earlier, they would not perform so poorly. This line brings the focus back to the structure of education before leading into S6, which blames the system. Step 5: Putting this together, we get S1 → R → Q → S → P → S6, that is R Q S P.

Verification / Alternative check:
Try any option where P comes directly after S1. The argument then jumps prematurely to an early start in medical education without first establishing the seriousness of the failure and the general ignorance among people. Similarly, if S is placed before Q, the author mentions a snake bite emergency before establishing a broader lack of hygiene knowledge, which weakens the logical build up. This confirms that R Q S P is the strongest sequence.

Why Other Options Are Wrong:
Option \"P R Q S\": P introduces a hypothetical about doctors starting earlier but does not logically follow S1 as strongly as R does, and the flow becomes disjointed. Option \"Q R P S\": Moving from S1 directly to household observations (Q) skips the clear connection provided by R that links epidemics and doctor performance to the education system. Option \"P Q S R\": This order scatters the argument; R, which contains a strong evaluative statement about education, is oddly pushed to the end of the middle block instead of building the argument.

Common Pitfalls:
Candidates sometimes look only at obvious sequence markers like \"if\" and \"so\" and ignore thematic progression. In paragraph ordering questions, always consider which sentence directly elaborates a key phrase in the previous one. Here, \"a serious blot on the state of our education\" in R is a clear echo of S1 and naturally follows it.

Final Answer:
The correct sequence of the middle sentences is R Q S P, giving a clear and coherent paragraph between S1 and S6.