251. Which types of rocks are mainly found in the Himalayan ranges ______? 252. The third (3rd) world comprises approximately ______ percent of world's human race? 253. The inclination of the Earth's axis to the orbital plane is ______? 254. Mohs' Scale is used to indicate the ______? 255. What can be maximum duration of totality for a solar eclipse ______? 256. The total surface area of the Earth is ______? 257. What is the approximate equatorial circumference of the Earth ______? 258. The Earth rotates around an axis pointing towards ______? 259. Latitude of a place is indicative of its ______? 260. The upper part of the mantle upon which the crust of the Earth floats is known as ______?