There are at least two methods．Induction （归纳法） （as described by Darwin ），or deduction （演绎法）（ as described by Einstein）．Both methods can produce amazing result．But only when you know which"direction"to go．

The steps are the same．They include：

Theory （理论）＝Explaining how things work

Experiment＝A way to test what's happening

Observation＝Something you notice

Together，these are called the scientific method．

Should you start from the"bottom"by collecting information and facts to prove and seeing where chat leads you？That's induction．Charles Darwin （1809﹣1882 ） supported this method．He spent years observing the appearance and behavior of animals in different places．From this，he created his theory of natural selection：animal and plants can change because of their environment．

Or should you start from the"top"by creating a theory and then seeing how it stands up to real life？That's deduction．Albert Einstein（1879﹣1955）was king here．He began with brave ideas．These theories often took years to prove by experiment．

A few of Einstein's ideas are still being examined．

In history，scientist have been solving problems using different methods．For example，while studying bacteria（细菌）．Fleming found that something on bread could kill bacteria harmful to human health．This led him to discover a new medicine．Newton suggested that all objects attract each other．His idea was proved later．

So which way better？That depends．Some researchers do experiment，and only later consider where their results may lead them．That's induction．But deduction needs you to suggest a theory that may or may not be supported by the information and facts．The best scientists are always ready to change methods when necessary．

56．How many steps are there in the scientific method　　

A.2

B.3

C.4

57．Deduction needs you to start from the　　

A．"bottom"

B．"middle"

C．"top"

58．Fleming used　　to discover a new medicine．

A．induction

B．deduction

C．theories

59．The last paragraph（段）tells us　　

A．which way is better

B．To get more facts

C to use proper methods

60．What can be the best title of the passage？　　

A．Deduction and induction

B．Darwin and Fleming

C．Theory and experiment．