____ red is a symbol of warmth, it can sometimes make people feel uneasy or even frightened.
________ material used for running tracks in schools across China may be ________ danger to children's health.
I sent a big bunch of flowers to the nurse as an ________ of thanks for her taking good care of my grandpa in the nursing home.
If you don't work hard,it will be of no ________ for others to help you.
Two of my friends are having their weddings on the same day,and I'm in a real ________ about which one to go to.
In a natural disaster,minutes and even seconds of warning can make the ________ between life and death.