Do you think you have what it takes to be a successful scientist? A successful scientist is generally a good observer． He makes full __21__ of the facts he observes． He doesn’t accept ideas which are not __22__ on obvious facts, and therefore __23__ to accept authority as the only truth． He always checks ideas __24__ and makes experiments to prove them．

The rise of modern science may perhaps be considered to__25__ as far back as the time of Roger Bacon, the wonderful philosopher of Oxford, who lived between the years 1214 and 1292．He was probably the first in the Middle Ages to __26__ that we should learn science __27__ observing and experimenting on the things around us, and he himself __28__ many important truths．

Galileo (1564－1642), __29__，who lived more than 300 years later, was the greatest of several great men in Italy, France, Germany, and England, who began to show how many important __30__ could be discovered by observation by degrees．Before Galileo, learned men believed that large bodies __31__ more rapidly towards the earth than small ones, __32__ Aristotle said so． But Galileo, going to the __33__ of the Leaning Tower of Pisa, let fall two __34__ stones and proved Aristotle was wrong．It is Galileo’s __35__ of going direct to nature, and proving our __36__ and theories by experiment, that has __37__ all the discoveries of modern science．