某台水泵在转速不变时，当输送的水温度增加时，其轴功率（）。
A、增加
B、降低
C、不变
D、先降低，后增加
参考答案：B
化简：-[-（-8）]=______；-[-（+8）]=______．
A．Because they think people are usually very interested in sports.
B．Because they are not interested in how jet lag affects businesspeople.
C．Because baseball teams want to know how to win more games.
D．Because it is difficult to measure how jet lag affects other types of travelers.
