Questions

The process which involves absorption of heat is endothermic.

Here given all the options are involving in absorption of heat. Hence, all the above are endithermic.

Most organic compounds contain carbon and hydrogen.

The capacity of a water heater is measured in Gallons or Liters. In the USA, it is measured in Gallons and in India, we measure it in Liters.

Hence, if the capacity of the water heater is 15 gallons or 15 liters, then it says that it can hold 15 gallons or 15 liters of water.

The process that occurs inside the chloroplasts is photosynthesis. The light from the sun is obserbed and combining with water and CO2, plants prepare food for the plants.

When backed by buying, power wants become demands. 

Of the two international ship canals, the Suez is more important than the Panama. Constructed over a period of 10 years according to a plan of the French Engineer  Ferdinand de Lesseps, the Suez Canal was opened as early as 1869.