P-1 Refraction of light — Science STD 10 — Question

………… is the only element in duplet state.

………… an alcohol is a clean fuel.

Fill in the following blanks with suitable words:
A person is short-sighted if his eyeball is too ____ Spectacles with a _____ lens are needed. A person is long sighted if his eyeball is too _____ Spectacles with a ____ lens are needed. These focus light rays exactly on to the _____.

………… and ………… can control the soil pollution occuring due to acid rain.

Fill in the following blanks with suitable words:
The theory of natural selection for evolution was proposed by _____.

Fill in the following blanks:
The response of leaves to the sunlight is called ________.

The ………… used in agriculture pollutes water.

Group II A elements are called as ………… .

Two rows shown separately at the bottom of the Modern Periodic table are called ………… and ………… .