The following passage is an article on Quantum Theory but some of the words are missing. Fill in the blanks with one suitable word each using from the given options :
Light is still one of the greatest mysteries to man. We (a) ................. that light travels in waves, and that light waves are made up of electrical (b) .................. magnetic forces travelling along together. They are a kind of electromagnetic waves. In 1900, a ** physicist (c) ............. Max Plank found that waves (d) ............. not tell the whole story about light. He was trying to explain how a hot object gives *** radiation.
(a) (i) know (ii) realise (iii) understand (iv) forget
(b) (i) with (ii) for (iii) and (iv) or
(c) (i) called (ii) named (iii) was (iv) known
(d) (i) did (ii) has (iii) have (iv) do
