单选题

　　1、The profit-sharing plan is designed to ______ the staff to work hard.

　　A、calculate

　　B、demonstrate

　　C、speculate

　　D、motivate

　　单选题

　　2、【完成句子】Did you know that before 1950, hurricanes had no names? They were simply given numbers. The first names were simply Alpha, Bravo, Charlie, etc. but in 1953, females names were given because of the unpredictability（不可预知）factor of the storms. In 1979, realizing the sexist（性别歧视的）nature of such names, the lists were expanded to include both men and women.

　　The main consideration of using males and females’ names for hurricanes is __________.

　　A、the timely（及时的）discover

　　B、its uncertainty

　　C、sex equality

　　D、its connection with humans