【单选题】You are____ to ask the teacher for permission if you want to leave the classroom.
【单选题】下列代码的执行结果是: var s = 'aaa_aa_a'; var r1 = /a+/g; var r2 = /a+/y; console.log("one: "+r1.exec(s)) console.log("two: "+r2.exec(s)) console.log("three: "+r1.exec(s)) console.log("four: "+r2.exec(s))
A.
one: aaa two: aaa three: aa four:aa
B.
one: aaa two: aaa three: aa four: null
C.
one: aaa two: aaa three: null four:aa
D.
one: aaa two: aaa three: undefined four:aa
【单选题】下面程序的执行结果为? fun1(); function fun1(){ console.log("A"); } var fun1 = function(){ console.log("B"); } function fun2(){ console.log("C"); } var fun2 = function(){ console.log("D"); } fun2();
【简答题】已知几个集成运放的参数如表 P4.3 所示,试分别说明它们各属于哪种类型的运放。 表 P4.3 特性指标 A od r id U IO I IO I IB - 3dB f H K CMR SR 单位增益带宽 单位 dB M Ω mv nA nA Hz dB V/ μ V MHz A 1 100 2 5 200 600 7 86 0.5 A 2 130 2 0.01 2 40 7 120 0.5 A...