/* 2699 */

 #include <iostream>

 #include <cstdio>

 #include <cstdlib>

 #include <cstring>

 #include <queue>

 using namespace std;

 #define MAXN 16

 typedef struct node_t {

     char x, y, d, c;

     bool f;

     node_t() {}

     node_t(char xx, char yy, char dd, char cc, bool ff) {

         x = xx; y = yy; d = dd; c = cc; f = ff;

     }

 } node_t;

 char map[MAXN][MAXN];

 char n = ;

 char ch;

 char dir[][] = {

     // right, down, diag(2)

     , , ,, , , ,-

 };

 bool check(char x, char y) {

     return x< || x>=n || y< || y>=n;

 }

 bool bfs(char xx, char yy) {

     queue<node_t> Q;

     node_t nd;

     char i, j, k;

     char x, y;

     for (i=; i<; ++i) {

         nd.x = xx + dir[i][];

         nd.y = yy + dir[i][];

         nd.d = i;

         nd.c = ;

         if (check(nd.x, nd.y))

             continue;

         if (map[nd.x][nd.y] == ch) {

             nd.f = false;

             Q.push(nd);

             x = xx - dir[i][];

             y = yy - dir[i][];

             if (!check(x, y) && map[x][y]=='.') {

                 nd.f = true;

                 nd.c = ;

                 Q.push(nd);

             }

         } else if (map[nd.x][nd.y] == '.') {

             nd.f = true;

             Q.push(nd);

         }

     }

     while (!Q.empty()) {

         nd = Q.front();

         Q.pop();

         if (nd.c==) {

             return true;

         }

         nd.x += dir[nd.d][];

         nd.y += dir[nd.d][];

         if (check(nd.x, nd.y))

             continue;

         --nd.c;

         if (map[nd.x][nd.y] == ch) {

             Q.push(nd);

         } else if (map[nd.x][nd.y]=='.' && nd.f==false){

             nd.f = true;

             Q.push(nd);

         }

     }

     return false;

 }

 int main() {

     int t, tt=;

     int w, b;

     char i, j, k;

     bool flag;

     #ifndef ONLINE_JUDGE

         freopen("data.in", "r", stdin);

         freopen("data.out", "w", stdout);

     #endif

     scanf("%d", &t);

     while (t--) {

         w = b = ;

         for (i=; i<n; ++i) {

             scanf("%s", map[i]);

             for (j=; j<n; ++j) {

                 if (map[i][j] == 'W')

                     ++w;

                 else if (map[i][j] == 'B')

                     ++b;

             }

         }

         ch = (w==b) ? 'B' : 'W';

         flag = false;

         for (i=; i<n; ++i) {

             for (j=; j<n; ++j) {

                 if (map[i][j]==ch && bfs(i,j)) {

                     flag = true;

                     goto _output;

                 }

             }

         }

         _output:

         if (flag)

             puts("YES");

         else

             puts("NO");

     }

     return ;

 }