Mary went to Viet Nam last year and it was her second time1/15Mary went to Viet Nam last year and it was her second time.That was the first time Mary went to Viet Nam.That wasn’t the first time Mary went to Viet Nam.That was the second time Mary went to Viet Nam.That was the last time Mary went to Viet Nam.Giải thíchĐáp án: C Dịch nghĩa: Đó là lần thứ hai Mary đến Việt Nam.