import sys
t=int(sys.stdin.readline().strip())
for _ in range(t):
    n=int(sys.stdin.readline().strip())
    a=list(map(int,sys.stdin.readline().split()))
    seen = set()
    b = []
    for x in a:
        if x not in seen:
            b.append(x)
            seen.add(x)            
    print(' '.join(map(str, b)))