I think the best technique for memorizing is by assigning meaningfulness to things that are to be memorized.

Or in other words, relating things with a memorable story, simply, creating a story.
Do you remember yourself teaching us to memorize things easily. We had related words to a story and almost everyone in the class remembered at least 25 words among the total of 30. I still remember "Bhachyeko Haat". Haha!

Memory export Jim Kwik says that anything combined with emotion becomes a...

1) That old man is Aksionov.

2) The speaker is asking about the truth of digging an escape hole .

3) The speaker means the prison's wall.

Yes, if the angle between the two vectors is more than 90^o but less than 270⁰. (cosΘ is negative)

The answer is A 

In the depletion layer, electrons combine with holes producing charge density so that region is depleted of charge carriers  but it has charge density .

Conclusion: Neutral but still having non zero charge density .