Andy was still traveling in Spain when he realized he had to confirm (确认) his flight home with the airline company (航空公司). He was visiting Spain in order to improve his Spanish. When he was speaking to people face to face, he had no difficulty understanding what they said. However, when he was speaking on the phone, he still had a problem. Andy called the airline. And the clerk confirmed that his plane was leaving at nine o'clock three days from that day. She also told Andy to be at the airport two hours earlier in order to check in his luggage and get a seat.

    Since he was leaving in three days, Andy didn't lose any time. He visited as many places as he could. He thought that it would probably be a while before he had enough money again. He wished he could come back and spend a year in Spain.

    Too quickly, the final day arrived. Andy left early for the airport to arrive two hours before take-off. He hated to rush. He went to the clerk to show his ticket. The clerk looked at the ticket in surprise. "Why, sir, but your flight was at nine o'clock in the morning, and now it is eight in the evening." "But I confirmed my flight," insisted Andy. "Will I have to pay for another ticket?"

    "No, sir. However, the next flight out will be three days from now."

    Andy's look of shock turned to pleasure as he realized that now he could continue his vacation.

已知关于x的一元二次方程(a－1)x²－2x+1=0有两个不相等的实数根,则a的取值范围是(      ).