The works of philosophers K,R,S,and W will be discussed in a series of four seminars.Each seminar in the series will be on exactly one of these philosophers, and no philosopher will be the focus of more than one of the seminers.The order in which these seminars can be conducted is constrained by the following conditions:
The seminar on W must be either the first or the last in the series.
The seminar on R must be conducted at some time before the seminar on S or at some time before the seminar on W but not before both.
The seminar on K cannot be the one immediately following the seminar on S.
通过以上三个条件筛选后，一共只有四中可能的情况 WRKS，WKRS， KSRW， SRKW
(1) Which of the following could be the order in whith the four seminars are conducted?
A. K,R,S,W
B. S,R,K,W
C. S,R,W,K
D. W,R,S,K
E. W,S,R,K
(2) If the frist seminar is on W,which of the following must be true? 只有两种 WRKS，WKRS
A. The seminar on R is immediately after the seminar on W.
B. The seminar on S is immediately after the seminar on R.
C. The seminar on K is conducted at some time after the seminar on R.
D. The seminar on R is conducted at some time after the seminar on K.
E. The seminar on S is conducted at some time after the seminar on K.
(3) If the seminar on S is conducted at some time before the seminar on K,which of the following must be true? 只有一种SRKW
A. The first seminar is on W.
B. The second seminar is on R.
C. The second seminar is on S.
D. The third seminar is on R.
E. The forth seminar is on K.
(4) If the seminar on K is the first seminar in the series,whith of the following must be true? 只有一种 KSRW
A. The second seminar is on R.
B. The second seminar is on S.
C. The seminar on K is immediately before the seminar on R.
D. The seminar on S is conducted at some time after the seminar on R.
E. The seminar on W is conducted at some time before the seminar on R.
(5) Which of the following can be true of the seminar series? 一比对就好了 WRKS，WKRS， KSRW， SRKW
A. The last seminar is on K.
B. The third seminar is on S.
C. The first seminar is on S and the third seminar is on R.
D. The seminar on S is conducted at some time before the seminar on K.
E. The seminar on W is immediately after the seminar on S.
(6) If the seminar on S is not the last seminar in the series,which of the following must be true? 可以为 KSRW， SRKW
A. The first seminar is on K.
B. The first seminar is on S.
C. The second seminar is on K.
D. The second seminar is on R.
E. The last seminar is on W.
如有不对，请留言，谢谢。