皮皮学，免费搜题
登录
搜题
【单选题】
由高中数学可知，对于连续函数f(x)，若f(x1)与f(x2)值的符号相反，则在x1和x2之间必存在x0，使得：f(x0)=0（该点称为"零点"）。设有VB函数：Private Function f(x As Single) As Single 可以返回f(x)的值（函数体没有给出）。下面程序的功能是从键盘输入2个实数x1、x2，判断在x1、x2之间是否存在零点。Private Sub Command1_Click() Dim x1 As Single, x2 As Single x1 = InputBox("请输入一个实数x1") x2 = InputBox("请再输入一个实数x2") If ( _______________ ) Then Print "在"; x1; "与"; x2; "之间存在零点" Else Print "不能确定在"; x1; "与"; x2; "之间是否存在零点" End IfEnd SubPrivate Function f(x As Single) As Single ……End Function为使上面程序可以实现该功能，程序代码中横线处应填写的代码是_______________。A.
f(x1) >0 Or f(x2) < 0
B.
f(x1) < 0 And f(x2) < 0
C.
f(x1) * f(x2) < 0
D.
f(x1) * f(x2) > 0
拍照语音搜题，微信中搜索"皮皮学"使用
参考答案：
参考解析：
知识点：
皮皮学刷刷变学霸
举一反三
【单选题】新药长期毒性试验,描述错误的是:
A.
一般行为活动宜每天观察记录
B.
试验中途允许改变剂量
C.
发现有阳性指标应加大观察密度
D.
啮齿类动物长期毒性试验中组均值的意义通常大于单个动物数据的意义
【简答题】已知函数y=f（x）是偶函数，当x＞0时，有 f(x)=x+ 4 x ，且当x∈[-3，-1]，f（x）的值域是[n，m]，则m-n的值是？
【单选题】Had you prepared for your lecture, you______ more fluently.
A.
should have spoken
B.
would have spoken
C.
would speak
D.
had spoken
【简答题】已知f（x）是奇函数，g（x）=f（x）+4，g（1）=2，则f（-1）的值是______．
【简答题】东巴文字是目前世界唯一存活着的象形文字,成为文字起源和发展的( )。
【简答题】某噬菌体可以携带供体DN段进入受体细胞中,但不能进行复制,这种噬菌体称为__________。
【简答题】I'm ashamed _____________ such a thing. [A] that you would have done [B] that you should have done [C] of what you are doing [D] to what you were doing
【单选题】There was a lot of fun at the party. You ________, but why didn't you? [ ]
A.
should come
B.
ought to have come
C.
may have come
D.
must have come
相关题目：