Acid rain is caused by a

1. SO₂, SO₃
2. SO₂, CO
3. CO, NH₃
4. SO₂, NO₂

Why should we conserve forests and wildlife?

1. To maintain balance
2. To protect biodiversity
3. To continue food chain
4. All of the above

Blood flows in arteries in spurts and is under pressure. Which of the following reasons support this statement?

P. Arteries transport blood from left ventricles.

Q. Blood in left ventricle is at a high pressure.

R. Arteries have valves.

1. Only P
2. Only Q
3. Only P and Q
4. Only P and R

The liquid which collects in the cavity of Bowman's capsule is

1. concentrated urine
2. blood plasma minus blood proteins
3. glycogen and water
4. used bile for excretion