Hey i hope this helps!
A
D
A
Answer:
it means to show a certain/specific way
She <span>had been working</span> on the project for 2 days before she finished it. So B is the only right one as it's a continuous action before an action with an exact defining past perfect continuous. Also there's a key word "for" that can help us to find out the tense.
Answer:
World War 1 soldiers had to fight at any time ,day or night.So European glowworms at night guided them.That is how they are clever.