Consider the following statements about Nepenthes/Pitcher plant:

A. This plant has leaves which are pitcher-shaped and the mouth is covered with a leaf.

B. This plant has a special smell that attracts insects to it.

C. This plant is very common in the cold deserts of Ladakh and Russia.

D. This plant can trap and eat small insects, frogs and even mice. These animals when land on the mouth of the plant, they get trapped and cannot get out of it.

The correct statements are

To determine the correct statements about the Nepenthes (Pitcher plant), let us analyze each statement individually:

Statement A: "This plant has leaves which are pitcher-shaped and the mouth is covered with a leaf."
This statement is correct. The pitcher-like structure is a modified part of the leaf. The apex of the leaf forms a lid which can open and close the mouth of the pitcher.

Statement B: "This plant has a special smell that attracts insects to it."
This statement is correct. The pitcher plant emits a sweet, pleasant odor to attract insects towards its trap.

Statement C: "This plant is very common in the cold deserts of Ladakh and Russia."
This statement is incorrect. Nepenthes is typically found in rain-forests, damp acidic soils, and nitrogen-deficient environments. In India, it is natively found in the tropical rain-forests of Meghalaya, not in the cold deserts of Ladakh or Russia.

Statement D: "This plant can trap and eat small insects, frogs and even mice. These animals when land on the mouth of the plant, they get trapped and cannot get out of it."
This statement is correct. Nepenthes is a carnivorous plant capable of trapping and digesting insects, frogs, and occasionally even small rodents or mice that fall into its slippery inner walls.

Therefore, the correct statements are A, B, and D.