Questions

Ans. B.
‘to stick to one’s guns’ means refuse to compromise or change, despite criticism. It is a phrasal verb hence we can’t make any changes in the prepositions used. The sentence is in past tense, hence stick should be replaced by stuck.

RNA is a single-stranded molecule in many of its biological roles and consists of a much shorter chain of nucleotides.

In 1887 Congress passed the Interstate Commerce Act, making the railroads the first industry subject to Federal regulation. Congress passed the law largely in response to public demand that railroad operations be regulated.

Railroads discriminated in the prices they charged to passengers and shippers in different localities by providing rebates to large shippers or buyers. These practices were especially harmful to American farmers, who lacked the shipment volume necessary to obtain more favorable rates.

Gujral Doctrine is considered as a milestone in India's foreign policy. It was rendered by Mr. Inder Kumar Gujral, the Minister of External Affairs in H. D. Deve Gowda Government in 1996. This theory says that "India" as a bigger country of South Asia should give one-sided concession to her small neighbours and have cordial relations with them.