1、perform

2、performance

3、period

4、periodical

5、perish

6、perpetual

7、perplex

8、perspective

9、pessimistic

10、optimistic

11、optimum

12、option

13、optional

14、organ

15、organic

16、organism

17、organization

18、organize

19、enhance

20、enlarge

21、enlighten

22、rake

23、rare

24、rarely

25、rate

26、ratio

27、rational

28、reach

29、react

30、realistic

31、reality

32、realize

33、select

34、selection

35、sense

36、sensation

37、sensible

38、sensitive

39、separate

40、sequence

41、serial

42、series

43、serious

44、toast

45、together

46、token

47、tolerance

48、tolerant

49、tolerate

50、accumulate

51、accuracy

52、accurate

53、accuse

54、achieve

55、acknowledge

56、cheer

57、chemical

58、cherish

59、chip

60、choice

61、choose

62、board

63、boast

64、bonus

65、boom

66、boost

67、verbal

68、verdict

69、verify

70、verse

71、version

72、vessel