某企业生产流水线M共有两位生产者，生产者甲不断地将其工序上加工的半成品放入半成品箱，生产者乙从半成品箱取出继续加工。假设半成品箱可存放n件半成品，采用PV操作实现生产者甲和生产者乙的同步可以设置三个信号量S、S1和S2，其同步模型如下图所示。
信号量S是一个互斥信号量，初值为 (6) ；S1、S2的初值分别为 (7) 。
（6）应选入（）。
A．0
B．1
C．n
D．任意正整数
参考答案：B
| 阅读理解。 | ||||
| In the recent years, people have shown their thanks, invitations, or hopes and wishes, or something else in different kinds of cards. Here are some cards below.
| ||||
| 1. ______ must be a teacher in a school. | ||||
[ ] | ||||
| A. Mr. Li B. Ben C. Lucy D. Mark | ||||
| 2. Tom expresses his ______ in his card.. | ||||
[ ] | ||||
| A. hopes B. wishes C. thanks D. invitation | ||||
| 3. Kate is going to ______ next Tuesday. | ||||
[ ] | ||||
| A. take midexams B. have a birthday party C. go on a vacation D. look after the dog. | ||||
| 4. Lily's good friends are going to her birthday party ______. | ||||
[ ] | ||||
| A. this Saturday B. next Tuesday C. on October 10th D. on June 16th | ||||
| 5. ______ has a dog. | ||||
[ ] | ||||
| A. Kate B. WangNan C. Mark D. Tom |