Questions

“To aid” means to give financial or material help. So, option 2 is the best-fit answer. Amplify- increase

The hormone adrenaline also called epinephrine is known as a stress hormone. In emotional upsets( like fear, anger etc.) this hormone is poured into the blood and it accelerates heart beat. The hormone acetylcholine decelerates heartbeat rate.

The common greenhouse gas containing only hydrogen and oxygen is H2O, this is water vapor.

The common greenhouse gases are water vapor, carbon dioxide, methane, nitrous oxide, and ozone.

The composition (chemical formula) of those gases are:

Water vapor: H2O
Carbon dioxide: CO2
Methane: CH4
Nitrous oxide: NO
Ozone: O3.

As you see the only one of those that contains only hydrogen and oxygen is H2O, water vapor.

Todar Mal was associated with land revenue reforms.

Raja Todar Mal was the Finance Minister of the Mughal empire during Akbar's reign. He was one of the Navaratnas in Akbar's durbar.

Saudi Arabia is the country in the world to have no cinema theaters.

With the exception of one IMAX theater in Khobar by Khalid, there were no cinemas in Saudi Arabia from 1983 to 2018, although there was occasionally talk of opening movie theaters, and in 2008 conference rooms were rented to show the comedy Mennahi.