In a sense, his nonchalance: is the epitomy of cool or; could be unemotional or; simply misunderstands the gravity of the problem.
The contemptuous nonchalance of her trailed hand irritated him.
The concise list of ingredients for an omelet are: eggs, milk, salt, pepper and anything additional you like yourself.
There was some animosity between the two: it appeared they were co-managers.
A colon means: note the following.
Your hair is red. Your eyes are blue. Explanation: "Your" indicates ownership. In other words "your" means "belonging to you". Do not confuse with "you're", it is entirely different "you're" means...