Two interleaved sequences (odds increase by 1; evens increase by 2): A, B, B, D, C, F, D; H, E, ?, ? Find the next two letters by continuing both subsequences in order.

Introduction / Context:
This puzzle contains a single series that is actually the weave of two ascending alphabetical sequences. Recognizing the odd-position stream and the even-position stream allows you to continue the pattern correctly.

Given Data / Assumptions:

• Partial sequence: A, B, B, D, C, F, D; H, E, ?, ?
• Alphabet indices A=1 … Z=26.
• The semicolon simply separates what follows next but the same two-stream rule continues.

Concept / Approach:
List letters in odd positions and even positions separately. The odd-position letters increase by 1 each time (A, B, C, D, E, F, …). The even-position letters increase by 2 each time (B, D, F, H, J, L, …). Then place them back in order to fill the next two slots.

Step-by-Step Solution:

Verification / Alternative check:

Why Other Options Are Wrong:

• E, F / F, G / F, I / J, K each breaks one of the two strictly increasing streams when interleaved by position.

Common Pitfalls:
Misreading the semicolon as a reset or failing to split the sequence into odd and even positions.

Final Answer:
J, F