13．
Your Nose knows
If I were to ask you to close your eyes and I gave you a piece of apple to eat，would you be able to tell me what it is just by tasting it？Of course，you could．Your tongue helps you know what different foods taste like．Do you know that foods would taste different if you did not have a nose？
What You Need
☆a friend to help
☆small pieces of any food like carrot，orange，banana-whatever you have
☆small pieces of apples，raw（uncooked） potato and （if you are brave） onion
What You Do
There are actually three different experiments．You and your friend should take turns trying them on each other．
Experiment 1：
Have your friend close her eyes and open her mouth．Give her a piece of the food and ask her to taste it．Then，ask her what she thinks it is．She will probably guess correctly．
Experiment 2：
While your friend has her eyes closed，give her a piece of raw potato．At the same time，hold a piece of apple right under her nose．Ask her to eat the potato and tell you what she thinks it is．She will say it is a piece of apple!You can even do it the other way around，and she will think she is eating a potato，or，perhaps，she won't be able to name what she is eating．
Experiment 3：（for the brave）
Take a piece of raw onion．You don't have to close your eyes this time．Press your nose closed with your other hand so that no smells can get into your nose．Now eat a small piece of the onion．Surprise!As long as you hold your nose，you will not be able to taste the onion．
The Science Secret
You already know the science secret．Your nose and your tongue work together to make food taste the way it does．Your tongue，however，can taste only certain flavors like salty，bitter，sour，and sweet．All of the other"tastes"are actually"smells"，and you need your nose to taste them．
Oh，you might use this science secret the next time you are forced to eat something you don't like the taste of．If you hold your nose while you eat it，you won't"taste"it
at all．
53．In Experiment 1，you shouldB before giving your friend a piece of food．
A．a(chǎn)sk her to taste the food
B．have her close her eyes
C．see if her guess is correct
D．a(chǎn)sk her to name the food
54．Why is Experiment 3for the brave？BecauseB．
A．you have to press your nose
B．you have to eat a raw onion
C．you do the experiment alone
D．you must keep your eyes open
55．What's the passage mainly about？D
A．Why different foods can smell the same．
B．Why some things smell better than others．
C．How smell changes the way we see things．
D．How smell affects the way food tastes．
56．What can we learn from the passage？D
A．Knowledge comes from personal experience．
B．Team work helps us to find out science secrets．
C．We should have courage while doing experiments．
D．We can't draw a conclusion simply from the feeling．
