Questions

Agriculture would be a good example of a purely competitive industry.

The device which is used to measure air pressure is called as barometer. If the barometer reading is rising, it indicates that the air pressure is increasing and if the reading is falling the air pressure is decreaing.

Therefore the answer for What travels around the world but stays in one spot is STAMP or any other thing that acts as a stamp does.

Ex. the letter in the envelope etc...

Since, Several things have the possibility, but the word travel evokes that it would move. 

DNA is made of nucleotides. And these Nucleotides are made of a pentose sugar deoxyribose, a phosphate, and a nitrogen-containing bases.

Hence, the given statement 'Nucleotides are made of a pentose only' is FALSE.

"If fertilization occurs, the corpus luteum is maintained by a hormone secreted by the developing embryo." is the only correct statement about the uterine cycle among the options.

Magnetism in materials is due to circular motion of electrons.

In India, the right to vote is provided by the Constitution and the Representation of People's Act, 1951, subject to certain disqualifications. Article 326 of the Constitution guarantees the right to vote to every citizen above the age of 18.