Trig引脚的功能为（）。

超声波传感器有（）个针脚，分别是（）。 A: 2；VC B: GND C: 3；VC D: GN E: Echo F: 3；VC G: GN H: Trig I: 4；VC J: GN K: Trig、Echo

超声波传感器模块中的那一个引脚用于发射超声波（ ）。 A: Vcc B: Trig C: Echo D: Gnd

化简三角函数表达式<img src="http://img1.ph.126.net/i0New2KyMz3LiF5MNUZIPA==/6597565646403144931.png" />? TrigFactor[(Sin[2x]-Cos[2x]+1)/(Sin[2x]+Cos[2x]+1)]|Simplify[(Sin[2x]-Cos[2x]+1)/(Sin[2x]+Cos[2x]+1),Trig→True]|TrigReduce[(Sin[2x]-Cos[2x]+1)/(Sin[2x]+Cos[2x]+1)]|Cancel[(Sin[2x]-Cos[2x]+1)/(Sin[2x]+Cos[2x]+1),Trig→True]

My mother a doctor is my father so is A: My mother is a doctor. So is my father B: My mother is a doctor. So my father is C: My mother is a doctor. My father is so.

Jack, a friend of ________, often comes to see us. A: my brother and my sister B: my brother’s and my sister C: my brother and my sister’s D: my brother’s and my sister’s

I had supper with my _________that evening. A: my father B: my mother C: my brother D: my grandpa

以下表达式中,正确的是( ) A: K'(MY) = c(MY) / c(M)c(Y) B: K'(MY) = [MY] / [M][Y] C: K(MY) = [MY]/ [M][Y] D: K(MY) = [M][Y]/ [MY]

_____________, they speak English. A: In my belief B: For my belief C: On my belief D: To my relief

【单选题】Seldom ________ to the downtown area, and ________________. A. did my grandmother go ; neither did my grandfather B. did my my grandmother go; nor my grandfather went C. goes my grandmother; neither my grandfather does D. my grandmother went; nor did my grandfather