Arrange the following words in the sequence in which they occur in the dictionary: 1. Herbivorous 2. Harmony 3. House 4. Honour 5. Helm

Introduction / Context:
This dictionary order question involves five words beginning with H: Herbivorous, Harmony, House, Honour and Helm. You must determine the correct alphabetical order in which they would appear on a dictionary page. This tests your precision with letter-by-letter comparison beyond the initial character.

Given Data / Assumptions:
- Words with indices:
1. Herbivorous
2. Harmony
3. House
4. Honour
5. Helm
- Standard English alphabetical ordering is used.

Concept / Approach:
First compare the second letter in each word since they all start with H. This splits the words into groups like “Ha…”, “He…” and “Ho…”. Then, within each group, you compare the third and subsequent letters. Use the fact that when all letters match up to a point, shorter words usually come before longer ones, but only after ties in earlier letters.

Step-by-Step Solution:
Step 1: Compare the second letters: Harmony → H a… Herbivorous → H e… House → H o… Honour → H o… Helm → H e… So the blocks are: “Ha…” (2), “He…” (1 and 5), and “Ho…” (3 and 4). Step 2: The “Ha…” word Harmony (2) comes first because a comes before e and o. Step 3: Among the “He…” words, compare third letters: Herbivorous → H e r… Helm → H e l… At the third letter, l comes before r, so Helm (5) comes before Herbivorous (1). Step 4: Among the “Ho…” words, compare third letters: Honour → H o n… House → H o u… n comes before u, so Honour (4) comes before House (3). Step 5: Combine all groups in order of their second letters: Harmony (2), Helm (5), Herbivorous (1), Honour (4), House (3) → 2,5,1,4,3.

Verification / Alternative check:
Imagine flipping through an English dictionary under the letter H. You would first see “ha…” entries, then “he…”, then “ho…”. Within “he…”, words beginning with “hel…” appear before those with “her…”. And within “ho…”, words starting “hon…” come before “hou…”. This confirms the order Harmony, Helm, Herbivorous, Honour, House, matching the index sequence 25143.

Why Other Options Are Wrong:
- 12543 starts with Herbivorous (1) instead of Harmony (2), ignoring that “ha…” must precede “he…”.
- 21534 reverses Helm and Herbivorous and misorders Honour and House.
- 12354 has Herbivorous before Helm and Honour before Harmony, which is alphabetically inconsistent.

Common Pitfalls:
People often assume that longer words should appear later without actually checking earlier letters, or they mix up the order of vowels a, e and o. To avoid errors, always scan the second letter, then third, and so on, grouping words systematically by shared prefixes.

Final Answer:
The correct dictionary sequence is Harmony, Helm, Herbivorous, Honour, House, giving the index order 25143.