Expressions cover all parts of our life. They may be around your ears every day. You may know a lot of Chinese expressions that describe how you feel. Here are some English ones for your enjoyment.
Have Your Heart in Your Mouth
This expression means that you’re really afraid or anxious about something. When your heart starts beating so much that you can feel a thumping(怦怦跳) in your throat, it may feel like you "have your heart in your mouth."
Have Butterflies in the Stomach
How did butterflies get in your stomach? Well, those really aren’t butterflies in there. It is a way of describing those nervous feelings you might get before a test or a very important decision.
These stomach flutters (跳动) are normal and happen to many people. Some people believe having a few butterflies might even help you perform better.    
Sick as a Dog
If you’ve ever been very sick, you may have used this expression. Because dogs eat just about anything they find, they often get sick. So it’s all right to describe someone who’s not feeling well as being "sick as a dog".    
Under the Weather
When it’s rainy all day outside, how would you feel? This expression comes from the idea that bad weather might hurt a person’s health and mood(心情).
小题1: The expression "__" is most probably used while you are watching a thriller.
A. have your heart in your mouth    B. sick as a dog    C. under the weather
小题2:Someone believes__ if you "have butterflies in the stomach" before a test.
A. you’re sure to fail      B. you will forget everything C. you might do better
小题3:It’s __ to say somebody is "sick as a dog" when he is not feeling well.
A. impolite   B. suitable       C. wrong
小题4:When somebody says "under the weather", he must feel     
A. upset      B. happy            C. calm
小题5:All expressions discussed in this passage are about      
A. health      B. habits           C. feelings