55.It appears that the writer tends to think highly of the person who sleeps on one side because ______ .
A. he /she always shows sympathy for people
B.he /she is confident,but not stubborn
C.he /she has more strengths than weaknesses
D.he/ she often considers annoying people
B
The Scientific Method
Did you ever wonder why the water level in a glass doesn’t change when the ice in the glass melts (融化)? To find out why, you can use the scientific method. Used by scientists in various situations, the scientific method is also a clear and logical way to solve many real-world problems, as the procedure below indicates.
|
Steps in the Scientific
Method |
Examples |
|
State the problem or
question. |
“Why doesn’t the water
level in a glass rise when ice melts?” |
|
Collect information
about the problem, using your own observations and research. |
You already know that
ice is frozen water. From your research, you learn that water and ice are
made of water molecules (分子). |
|
Form a hypothesis, or a
best guess based on the information. |
“The molecules in water
appear to be closer together than they are in ice.” |
|
Test the hypothesis by
doing an experiment. |
Fill four glasses with
ice. Then pour water over the ice and fill each glass to the rim. As the ice
melts, you observe that the water does not spill over the top of the glasses.
Each time you repeat the experiment, you get the same results. |
|
Draw a conclusion based
on your results. |
Molecules are closer
together in water than they are in ice. |