Questions

Darjeeling is in West Bengal and other two are in Himachal Pradesh.

For an atom to emit X-rays it should have difference in energy levels

Tropical grasslands, or savannas, are also the homes of primates in Africa and Asia; no savanna-living primates exist in South America. Tropical grasslands comprise a mixture of trees and grasses, the proportion of trees to grass varying directly with the rainfall.

Here the given compound is MgSO4.

In the given compound, Sulphur (S) and Oxygen (O) are two non metals and Magnesium (Mg) is a metal.

In this compound, Sulphur and Oxygen reacts to form covalent bond and the metal Magnesium reacts with both non metals Sulphur and Oxygen to form ionic bonds.

Hence, in the given compound MgSO4 there are both covalent and ionic bonds.

Eukaryotic cells all have a nucleus. Eukaryotes are organisms that are multicellular, although there are some examples of single cellular eukaryotes. So eukaryotic cells can be either cell with a nucleus or a eukaryotic organism's cell.

The most important feature to judge whether it has nucleus membrane.

And for other choices, they are the common features of eukaryote and prokaryote.

A computer has a CPU which is called as Central Processing UNit or a Processor builton the mother board. It has many components like control unit and Arithmetic and logical unit. 

The Arithmetic and logical unit of the CPU performs the arithmetic operations or mathematical calculations.