何谓原生苷、次生苷？举例说明。

根据短文内容，选择最佳答案。

As teenagers, you have many dreams. These dreams can be very big, such as winning the Nobel Prize, or they can be small. You may just want to become one of the ten best students in your class. Once you find a dream, what do you do with it? Do you ever try to make your dream real?
Follow Your Heart by Australian writer Andrew Matthews tells us that making our dreams real is life’s biggest challenge.
You may think you’re not very good at some school subjects, or that it is impossible for you to become a writer. These kinds of thoughts stop you from getting your dream, the book says.
In fact, everyone can make his dream come true. The first thing you must do is to remember what your dream is.
Don’t let it leave your heart. Keep telling yourself what you want. Do this step by step and your dream will come true faster because a big dream is, in fact, many small dreams.
You must also never give up your dream.
There will be difficulties on the road to your dreams. But the biggest difficulty comes from yourself. You need to decide what is the most important. Studying instead of watching TV will lead to better exam results, while saving five Yuan instead of buying an ice cream means you can buy a new book. As you get closer to your dream, it may change a little. This is good as you have the chance to learn more skills and find new interests.
小题1:Follow Your Heart is

A．the first thing you must do to make your dream real

B．the most important dream to have for teenagers

C．the name of a famous Australian writer

D．the name of a book by Andrew Matthews

小题2:If you want to make your dream real, you should __

A．remember what your dream is	B．keep telling yourself what you want
C．never be afraid of difficulties	D．try to start with all the things above

小题3:From the text, we know the word "challenge" means

A．变化

B．挑战

C．决定

D．杰摩

小题4:What shouldn’t be done to make your dream come true?

A．Always remember what your dream is.	B．Watch TV instead of studying.
C．Do what you should do step by step.
D．Read more books, learn more skills and find new interests.

小题5:What is the best title for the text?

A．Keep Your Dream in Your Mind	B．How to Find Your Real Dream
C．Never Stop Dreaming of Success	D．Teenagers Have Many Dreams