有若干个数,第一个数记作a 1 ,第二个数记作a 2 ,第三个数记作a 3 …,第n个数记作a n ,若a 1 =-0.5,从第二个数开始,每个数都等于1与它前面的数差的倒数. (1)计算 a 2 =______; a 3 =______; a 4 =______. (2)猜想 a 1998 =______; a 2000 =______.
【简答题】Complete the following sentences w it h wards chosen tom the box below You may not use a ny wo rd s mo r e th an once. Change the form where necessary. o ptimal condone descend fundamental drawback s ...