Sir Isaac Newton was a scientist who discovered the law of gravity(重力). People have learned that Isaac Newton once ___(1)___ when he was thinking under an apple tree. __(2)__ he was woken up by an apple falling on his head. He jumped up, shouting, “Gravity made the apple fall!”
Did the apple really fall on him? No one __(3)__ for sure. The story of the apple may have some __(4)__, but people who knew him have written that it never happened. Newton had actually been studying gravity and thinking about how apples fell down from a tree and not __(5)___ for many years.
(1). A. fell overB. fell asleepC. fell ill
(2). A. SuddenlyB. SlowlyC. Usually
(3). A. promisesB. forgetsC. knows
(4). A. truthB. purposeC. requirement
(5). A. insideB. offC. up