en.javascript.info/archive/02-external-script/2-async-defer-first/solution.md

Answers:

1. The first is big.js, that's a normal sequence for external <script> tags.
2. The first is small.js, because async makes script behave independently of each other and the page. The first to loads runs first.
3. The first is big.js, because "deferred" scripts keep relative execution order.