Directions: There are 4 passages in this part. Each of the passages is followed by 5 questions or unfinished statements. For each of them there are 4 choices marked A, B, C and D.
Passage One

One of Britain’s bravest women told yesterday how she helped to catch suspected (可疑的) police killer David Bieber, and was thanked with flowers by the police. It was also said that she could be in line for a share of up to the ￡30,000 reward money. Vicki Brown, 30, played a very important role in ending the nationwide manhunt. Vicki, who has worked at the Royal Hotel for four years, told of her terrible experience when she had to steal into Bieber’s bedroom and to watch him secretly. Then she waited alone for three hours while armed police prepared to storm the building. She said: "I was very nervous. But when I opened the hotel door and saw 20 armed policemen lined up in the car park I was so glad they were there. " The alarm had been raised because Vicki became suspicious (怀疑) of the guest who checked in at 3 pm the day before New Year’s Eve with little luggage and wearing sunglasses and a hat pulled down over his face. She said: "He didn’t seem to want to talk too much and make any eye contact (接触)." Vicki, the only employee on duty, called her boss Margaret, , and husband Stan McKale, 65, who phoned the police at 11 pm. Officers from Northumbria Police called Vicki at the hotel in Dunston, Gateshead, at about 11:30 pm to make sure that this was the wanted man. Then they kept in touch by phoning Vicki every 15 minutes. "It was about ten past two in the morning when the phone went again and a policeman said ’Would you go and make yourself known to the armed officers outside’ My heart missed a beat." Vicki quietly showed eight armed officers through passages and staircases to the top floor room and handed over the key. "I realized that my bedroom window overlooks that part of the hotel, so I went to watch. I could not see into the man’s room, but I could see the passage. The police kept shouting at the man to come out with his hands showing. Then suddenly he must have come out because they shouted for him to lie down while he was handcuffed (戴上手铐)."

Directions:Vicki became suspicious of David Bieber because ______.