[阅读选择]Parents often decide on the basis of what their children want. Cathy， a mother told us， “My children have packed lunches， because they say they hate school dinners. I make 3 packed lunches every morning， so our kitchen is like a sandwich bar in the morning.” However， another mother， Susan made her choice based on the nutritious value of the food. She said， “My daughter always has school dinners. I think she probably gets healthier food by having a cooked lunch at school than she would if I made a few sandwiches.”
Which of the following is TRUE according to the passage?
A、Katz thinks chips are good for his kids.
B、Susan‘s daughter likes eating sandwiches.
C、Cathy may have at least three children.
D、Jamie likes burgers and pizzas.
答案解析：答案选C。细节查找并简单推断题。从本段，特别是I make 3 packed lunches every morning…可知Cathy有三个孩子在上学，有没有不上学的孩子不得而知，故选项C为最佳选项。其他三项均与原文意思不符。
Scientists have learned that the sense of pain is made up of both chemical and electrical signals. ________. Scientists also have learned that the nervous system sends two different kinds-of pain messages to the brain： one very fast， the other slow.
A、It tells us not to use the injured part until it heals.
B、These signals travel from nerve cells in the injured area， up the spinal cord(脊髓)to the brain， and back down again.
C、The first message is the warning signal.
D、The other message moves at a speed of only one meter a second.