计算机启动DOS有哪几种方式？

A successful scientist is generally a good observer.  He makes full 36  of the facts he observes.  He doesn’t accept ideas which are not  37   on obvious facts,  and therefore refuses to accept authority as the only   38   for truth.  He always  39    ideas carefully and makes experiments to prove them.
The rise of    40    science may perhaps be considered to    41   as far back as the    42    of Roger Bacon,  the wonderful philosopher of Oxford,  who live    43    the years 1214 and 1292.  He was probably the first in the Middle    44    to suggest that we must learn science    45    observing and experimenting on the things around us,  and he himself    46   many important discoveries.
Galileo,  however,  who lived more than 300 years later (1564-1642),  was the greatest of several great men,     47    in Italy,  France,  Germany,  or England,  began by    48    to show how many important    49    could be discovered by observation.  Before Galileo,  learned men believed that large bodies fell more    50    towards the earth than small ones,     51    Aristotle said so.  But Galileo,  going to the    52     of the leaning Tower of Pisa,  let fall two  53    stones and proved Aristotle was wrong.  It was Galileo’s    54    of going direct to Nature,  and proving our    55    and theories by experiment,  that has led to all the discoveries of modern science.

小题1:	A．use B．time C．speed D．trust

小题2:	A．worked B．based C．lived D．written

小题3:	A．reason B．cause C．advice D．result

小题4:	A．thinks B．checks C．has D．learn

小题5:	A．natural B．physical C．ancient D．modern

小题6:	A．date B．keep C．look D．take

小题7:	A．study B．time C．year D．birth

小题8:	A．both B．each C．between D．among

小题9:	A．Schools B．Ages C．Days D．Count

小题10:

A．in B．with C．on D．by

小题11:

A．did B．made C．took D．gave

小题12:

A．who B．when C．that D．where

小题13:

A．ways B．degrees C．levels D．chance

小题14:

A．truths B．problems C．people D．subjects

小题15:

A．slowly B．rapidly C．lightly D．heavily

小题16:

A．although B．because C．when D．If

小题17:

A．place B．foot C．top D．ceiling

小题18:

A．big B．small C．equal D．unequal

小题19:

A．spirit B．skill C．theory D．discovery

小题20:

A．plans B．opinions C．world D．ability