Fill in the blank (vi).

Directions: Fill in the mentioned blank with the help of the alternatives given.

Trees are of _______(i)_______ importance for the environment. They balance the nature by _______(ii)_______ the temperature and humidity in the atmosphere. As a matter of fact, trees help humans in many _______(iii)_______. They _______(iv)_______ poisonous carbon dioxide and _______(v)_______ pure oxygen. Water cycle becomes possible due to trees. Moreover, trees _______(vi)_______ most of the pollution in the water. They keep the soil _______(vii)_______ by holding the soil particles with the help of roots. In addition, trees provide _______(viii)_______ to millions of plants and animals. Not only this, _______(ix)_______ of trees adds _______(x)_______ to the nature.