Although some groups of people have always lived outdoors in tents, camping as we know it today only began to be (56) _________ about 50 years ago.Đoạn văn56/70Although some groups of people have always lived outdoors in tents, camping as we know it today only began to be (56) _________ about 50 years ago.famouspopularfavouritecurrentGiải thíchB. popular