This factory strictly controls the emission of hydrogen sulphide.

The troposphere is the lowest part of the Earth's atmosphere, and most of the weather occurs here.

Carina is one of the constellations in the southern hemisphere.

He is good at playing the contrabass.

My younger sister won the piano contest.

He always carries a condom with him.

It is important to understand the basis of this problem.

This train is crowded every morning.

The air conditioner has broken down, so it needs to be repaired.

Good communication is the key to success.