An unlucky Singaporean thief picked up six years of hard labor after the unique (独特地) ring of the mobile phone he stole led police straight to him．Pretending to be a police detective, Rahman Magundario robbed two teenagers in a park, told them to turn their backs and stole the $ 140 phone, court documents show．If he had chosen another target (目标) in the mobile mad city state, he might have got off the hook．His number was up a short while later when the victim (受害人) heard the characteristic tune he had programmed into the phone．An unsuspecting buyer, who paid $ 70 in a coffee shop for what he thought was Magundario's mobile, pointed police to the thief．The 39-year-old was sentenced for threatening the teenagers and pretending a police officer．He got six years of corrective training, a court official said．It's worse than a prison sentence．

1．The police caught the thief without any difficulty mainly because________．

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A．the buyer pointed police to the thief

B．the thief pretended a police officer

C．the ring of the stolen mobile phone was different from that of others

D．the thief robbed two teenagers in a park

2．It can be learned from the text that Magundario________．

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A．stole the phone for money

B．sold the mobile phone for its unique ring

C．pretended a police officer because he looked like a policeman

D．was sentenced six years in prison

3．What can be inferred from the story?

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A．Many people in the city have mobile phones．

B．The thief would rather pick up six years of hard labor．

C．The thief would have escaped being caught if he hadn't sold the stolen phone．

D．The police recognized the thief when they heard the ring．

4．By saying his number was up a short while later, the writer means________．

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A．the thief knew the mobile phone number soon afterwards

B．the thief lost his luck before long

C．the thief forgot the mobile phone number a moment later

D．someone dialed the mobile phone number soon