单选题
● 设某系统由 P1 和 P2 两个子系统组成,当且仅当两个子系统都能正常工作时,该系统才能正常工作。若 P1 和 P2 的可靠性均为 0.9,则该系统的可靠性是 (10) 。
(10)
C
举一反三
Fatal error: Uncaught Error: Call to a member function query() on null in F:\duqu8.com\SaxueFrame\common\funarticle.php:16
Stack trace:
#0 F:\duqu8.com\SaxueFrame\common\funarticle.php(51): formatContent('<p>\xE2\x97\x8F \xE5\x9C\xA8 Exce...', Object(blockquestionlist))
#1 F:\duqu8.com\SaxueFrame\blocks\block_questionlist.php(107): formatQuestion(Array, Object(blockquestionlist))
#2 F:\duqu8.com\SaxueFrame\lib\template\template.php(640): blockquestionlist->setcontent(true)
#3 F:\duqu8.com\SaxueFrame\data\compiled\templates\wap\question.detail.html.php(354): saxue_get_eloop(Array)
#4 F:\duqu8.com\SaxueFrame\lib\template\template.php(329): include('F:\\duqu8.com\\Sa...')
#5 F:\duqu8.com\SaxueWap\detail.php(81): saxuetpl->fetch('F:/duqu8.com/Sa...')
#6 {main}
thrown in
F:\duqu8.com\SaxueFrame\common\funarticle.php on line
16