单选题库

int N;
cin >> N;
int cnt = 0; // 记录N被整除的次数
for(int i=1; i<N+1; i++)
    if(_____________)
        cnt +=1;
if(cnt == 2)
    cout << N << "是质数";
else
    cout << N << "不是质数";

int N = 10;
while(N){
    N -= 1;
    if(N%3 == 0)
        cout << N << "#";
}

int tnt = 0;

for(int i=0; i<10; i++)
    if(i%3 && i%7)
        tnt += i;
cout << tnt << endl;

for(int i=-10; i<10; i++)
    cout << i << " ";

int N;
cin >> N;
if(N% 3 == 0)
    cout << "能被3整除";
else if (N % 7 == 0)
    cout << "能被7整除";
else
    cout << "不能被3和7整除";
cout << endl;