题目

根据短文内容，从方框中选择恰当的选项填空（有两项多余）。 A. least B. Although C. body D. program E. twice F. together G. Internet H. hardly I. junk J. almost K. relax L. such Hello!I'm John. I'm in a health club now. I'm interviewing (采访) four students. Here are the results. My name is David. Ididany exercise in the past. So, I felt tired. Then I come here to exercisemyself. Good health makes myandmind great and helps me study well. I come herea week I exercise for thirty minuteseach time. I'm Alice. I was fat half a year ago. I likedeatingfoodwith a c在德国不莱梅举行的第48届世乒赛期间，某商场橱窗里用同样的乒乓球堆成若干堆“正三棱锥”形的展品，其中第1堆只有一层，就一个球，第2、3、4、…堆最底层（第一层）分别按下图所示方式固定摆放，从第二层开始，每层的小球自然垒放在下一层之上，第n堆第n层就放一个乒乓球，以f（n）表示第n堆的乒乓球总数，则f（3）=    ；f（n）=    （答案用n表示）．