双桨纵列式直升机是靠什么消除其反扭矩().
A.尾桨
B.周期变距
C.双旋翼反向旋转
D.挥舞运动
参考答案:C
I have only _____ uncle. His birthday is May _____ . [ ]
A. one; one
B. first; one
C. one; first
D. first; first
有如下程序:#include<iostream>using namespace std;class A{public: static int a; void init(){a=1;} A(int a=2){init();a++;}};int A::a=0;A obj;int main(){ cout<<obj.a; return 0;}运行时输出的结果是
A.0
B.1
C.2
D.3