A、When our work is over. B、At regular intervals each day. C、When we are in the best mood. D、When we feel hungry. B四个选项描述的都是时间。文中

Our eating habits are very important for good health and a strong body. There are times when most of us would rather eat sweets and ice cream than meat and rice. Sweets and ice cream are not bad for the stomach if we eat them at the end of a meal. If we eat them before a meal, they may take away our appetite. It is important for us to eat our meal at the same time each day. When we feel hungry, it is a sign that our bodies need food. When we feel angry or excited, we may not want to eat. When we are worried, we may not want to eat, either.
    A long time ago, in England, some judges used to decide whether a man was telling the truth by giving him some dry bread. If the man could not swallow the bread, it was a sign that he wasn’t telling the truth. He was telling a lie. Although this seems very strange and rather foolish, it is indeed an excellent way of finding out the truth. A man who is worrying about something has difficulty in swallowing anything dry. Because when he is worrying, he loses his appetite and does not want to eat.
16. Which of the following may take away our appetite before we have our meal?
17. When had we better have our meals?
18. How could the judges in old England tell that a man had told a tie?