一个较长时间内的时间序列的逐渐变化称为（）。
A.周期性
B.循环
C.回归
D.趋势
参考答案：D
In the competition to be held, a gold medal, together with a certain sum of money, _____ the champion.
will be given to who will win B. will be given to whoever will become
has been given to whoever wins D. was given to anyone who became
即彼成我败所由判也判：
