Question

1. The book entitled "De Philosophiae Naturalis Principal Mathematical" was written by................

2. ...............is the secondary air pollutant.

3. Rain or snow having pH less than 5.6 is known as................

4. The comet which returns once every 74 to 79 years is.................

Answer 1

1. Isaac newton

2. Ozone

3. Acid rain

4. Halley's Comet

Answer 2

1.sir Isaac Newton
2.ozone,no2,acid rain etched
3.acid rain
4.halley comet