Questions

Compound word means when two or more words join together to make a single word that gives a new meaning.

Here in the options, Self-evident is the compound word.

DNA - Deoxyribonucleic acid is a type of nucleic acid. The sugar contained in it is called Deoxyribose.

Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are low-pressure areas which, along with the anticyclones of high-pressure areas, drive the weather over much of the Earth.

Middle latitude cyclones are fueled by air high in the atmosphere.

Himachal pradesh 

Water is capable of dissolving a variety of different substances, which is why it is such a good solvent.

And, water is called the "universal solvent" because it dissolves more substances than any other liquid

It means that wherever water goes, either through the ground or through our bodies, it takes along valuable chemicals, minerals, and nutrients

The atmosphere is a mixture of several gases. Nitrogen is the most abundant gas in the atmoshere and oxygen is next to it. It is 78% in the atmosphere and 21% is oxygen. Remaining 1% is all other gases like argon, hydrogen, neon, etc...

A complex sentence is a sentence that contains an independent clause and one or more dependent clauses.

If two clauses are connected with a coordinating conjunction, it's a compound sentence.

If two clauses are connected with a subordinating conjunction, it's a complex sentence.