GRE模拟题：自测试题二（5）

　　In a benefit concert each of exactly seven solo performers-Harris, Jones, McIntyre, Nelson, Strapp, Trevino, and Williams-will sing. The concert director is deciding the order in which the performers will sing and is assigning each to exactly one of seven time slots, numbered consecutively 1 through 7, according to the following conditions:

　　Harris must sing at some time before McIntyre sings.

　　Strapp must sing at some time before Jones sings.

　　Trevino must sing either immediately before or immediately after Nelson sings.

　　Williams must be assigned to time slot 3.

　　13. Which of the following could be the order, from first through seventh, in which the performers sing?

　　(A)Harris, McIntyre, Williams, Trevino, Nelson，Strapp, Jones

　　(B)Jones, Harris, Williams, Strapp, McIntyre，Nelson, Trevino

　　(C)Strapp, McIntyre, Williams, Nelson, Trevino，Harris, Jones

　　(D)Trevino, Harris, Williams, Strapp, Nelson, Jones，McIntyre

　　(E)Trevino, Nelson, Harris, Strapp, Williams，McIntyre, Jones

　　14. If there are exactly four performers who are to sing after Nelson sings but before Strapp sings, Harris must be assigned to time slot

　　(A)1

　　(B)2

　　(C)4

　　(D)5

　　(E)6

　　15. If Williams is to sing immediately after Harris sings and immediately before Trevino sings, which of the following performers could be assigned to time slot 6?

　　(A)Harris

　　(B)Jones

　　(C)Nelson

　　(D)Strapp

　　(E)Trevino