576: Which one of the following statements is correct with reference to our solar system ?
(a) The Earth is the densest of all the planets in our solar system
(b) The predominant element in the composition of Earth is silicon
(c) The Sun contains 75 per cent of the mass of the solar system
(d) The diameter of the Sun is 190 times that of the Earth
577: Ebraham Alkazi is an eminent personality in which one of the following areas?
(a) Heart surgery
(b) Transport engineering
(c) Theatre training
(d) Civil aviation
578: Sugarcane, sugarbeet, sweetpea, chickpea, pigeonpea and French bean belong to
(a) two plant families
(b) three plant families
(c) four plant families
(d) five plant families
579: Which one of the following vitamins is considered to be a hormone ?
(a) A
(b) B
(c) C
(d) D
580: Consider the following statements :
Chlorofluorocarbons, known as ozone-depleting substances, are used
1. in the production of plastic foams
2. in the production of tubeless tyres
3. in cleaning certain electronic components
4. as pressurizing agents in aerosol cans
Which of the statements given above is/are correct?
(a) 1, 2 and 3 only
(b) 4 only
(c) 1, 3 and 4 only
(d) 1, 2, 3 and 4