单词拼写。

1. I am unable to c_____ to school because my bicycle is broken.

2. If it were not for this s_____, he is afairly good teacher.

3. The airliner flew at an a_____ of 20, 000ft.

4. He looks down from the top of the mountain to the v_____ far below.

5. As you get older your a _____ towards death changes.

( )的另一个主要用途是对原始数据进行预处理，以消除数据中的异常因素或除去数据中的周期变动成分。

A．简单移动平均法
B．指数平滑法
C．趋势外推法
D．因果分析法