We should abide by the rules.

We shall discuss about the matter. = We shall discuss the matter.

We reached the station after the train had come.

We must help him. (Negative) = We can not but help him.

We must guard against our mistakes.

We learn from mistake.

Warn of = সর্তক করা = They warned him of the dangers of sailing alone.

Vixen = Fox

Very few persons in the office are as health as he. = He is the healthiest person in the office.

up and doing = You should be up and doing 

Under the thumb (কারো কর্তৃত্বাধীন)= He was still under his father's thumb.

Twenty years ago, I was leaving in Paris (Make it compound).

= It was twenty years ago and I was living in Paris.

Turn down (অগ্রাহ্য করা) She turned down my proposal.

True = সত্য

Bangladesh was not independent before. Others administered the country and exploited its propaganda. So it happened in 1971. About three million brave children died in this war. We celebrate them with respect.