【课前预习】
1. The police chief advised his men to keep _____ and not lose their temper.
A. calm B. quiet C. still D. silent
2. Color-blind people often find is difficult to _____ blue from green.
A. judge B. tell C. divide D. separate
3. He smiled politely ______ Mary apologized for her drunken friends.
A. As B. If C. Unless D. though
4. __________ the size of the universe, some researchers believe that there is life beyond our planet.
A. Consider B. To consider C. Considered D. Considering
5. The glorious moment would live in my mind _____ our football team won the championship.
A. when B. where C. that D. which
