1616: Lead, ingested or inhaled, is a health hazard. After the addition of lead to petrol has been banned, what still are the sources of lead poisoning?
1. Smelting units
2. Pens and pencils
3. Paints
4. Hair oils and cosmetics
Select the correct answer using the codes given below :
(a) 1, 2 and 3 only
(b) 1 and 3 only
(c) 2 and 4 only
(d) 1, 2, 3 and 4
1617: Which organelle in the cell, other than nucleus, contains DNA ?
(a) Centriole
(b) Golgi apparatus
(c) Lysosome
(d) Mitochondrion
1618: Pneumoconiosis afflicts the workers who work mainly in:
(a) Tanneries
(b) Coal mining industry
(c) Glass industry
(d) Distilleries
1619: Magasthenes visited the court of:
(a) Ashoka
(b) Harsha
(c) Chandragupta Maurya
(d) Vikramaditya
1620: A box contains 5 sets of balls while there are 3 bails in each set. Each set of balls has one colour which is different from every other set. What is the least number of balls that must be removed from the box in order to claim with certainty that a pair of bails of the same colour has been removed?
(A) 6
(B) 7
(C) 8
(D) 9