Meteor Crater in Arizona is a circular pit 4200 feet across and 570 feet deep, with a sloping rim that rises 150 feet. Even to a layman, the crater looks as if it must have been made by a giant explosion. The outer slopes are littered with crushed and pulverized rock, some of which is scattered for miles around. Slabs ten feet thick and weighing thousands of tons are found a half a mile away. Lumps of nickel and iron, ranging in weight from a fraction of an ounce to more than half a ton are scattered for miles around the crater.

Sheep herders who saw the crater in 1871 picked up lumps of metal and concluded that a star must have fallen, but the scientists of the day disagreed. They argued that meteorites sometimes fell with great force and buried themselves several feet in the ground, but would not admit to a meteorite large enough to open a hole the size of Meteor Crater.

Q. Underline the sentence which suggests that events which occur for the first time are often treated with disbelief.