# cs = int(input())
# for i in range(cs):
#     n = input()
#     num =list(map(int,input().split()))
#     b = set(num)
#     ans = list(b)
#     print(" ".join(str(x) for x in b))
cs = int(input())
for _ in range(cs):
    n = input()
    num =list(map(int,input().split()))
    print(" ".join(str(x) for x in list(dict.fromkeys(num))))

dict.fromkeys（） 有序去重，set无序去重