18. The most densest substance on the Earth is
(A) Platinum
(B) Copper
(C) Steel
(D) Osmium
19. A camera uses a __________ to form an image.
(A) convex lens
(B) concave lens
(C) condenser lens
(D) none of these
20. Which from the following is NOT a conductor?
(A) Aluminium
(B) Silicon
(C) Graphite
(D) All are conductors
21. Hazrat Ali (R.A) was martyred in the __________ Hijrah.
(A) 36
(B) 38
(C) 40
(D) 42
22. Which country is called the “Land of Prophets”?
(A) Saudi Arabia
(B) Iraq
(C) Syria
(D) Palestine