Explanation

The preposition "by" is used to indicate a point of time or deadline.

Here, it means the train is late and will arrive by 6 hours (i.e., by 6 o’clock).

Explanation

The phrase "blew up" means to destroy or explode something, which fits the context of soldiers destroying a bridge.

The sentence means: Before going, soldiers destroyed the bridge by exploding it.

Explanation

Explanation

The word "Fortunately" implies the speaker was in a safe place — being inside a building provides protection during a storm.

The preposition "inside" correctly indicates location within the building, making the sentence meaningful and complete.

Explanation

The phrase "set up" means to establish or start something, such as a business.

The sentence refers to the State Bank providing loans to young people to establish or start their own businesses.