题目内容：

    It was just a normal day for Ruth Miller, a 63-year-old woman until everything went horribly wrong. She was walking to her car after shopping when the unthinkable happened.

Right as she was unlocking her car, a man quickly came up behind her and tried to wrestle her purse away. She was in shock. Luckily she remembered she had her Safe Personal Alarm (SPA) on her purse, and since she was too scared to scream for help, she quickly reached for the alarm and pulled the pin (保险栓). Immediately her SPA started just screaming. The man didn't know what to do! He froze for a second, and then ran away like a bat out of hell!

SPA is a safety device capable of creating a 125db sound that attracts attention and scares away potential attackers. To compare, it's the same volume as a military jet during takeoff.

Paul Davidson, the inventor of SPA, knows all too well the type of situation that Ruth found herself in. But that's not the only type of situation that SPA helps protect against. Parents can give it to their kids as an extra means of protection. Teenagers can use it so they can feel safe walking home. Women can know it's there when they have to use the parking lot at night. “My mother, who is 76 years old, carries it around in case she falls and needs to ask people for help. I only wish I'd have thought of it earlier,” said Paul.

The police have been recommending SPA since it first hit the market. In fact, since its launch, SPA has been in a state, shifting between in stock to sold out nearly every other week, and it's also got tons of loyal followers worldwide.

1.What does the underlined part “the unthinkable” in Paragraph 1 refer to?

A.An attempted robbery. B.A wrestling match.

C.An angry argument. D.A car accident.

2.How did Ruth react to the unexpected situation?

A.She fought violently. B.She froze in great fear.

C.She cried desperately for help. D.She sounded her safety device.

3.Why does Paul mention his mother?

A.To imply the elderly need more care. B.To suggest he cares about his mother.

C.To show SPA can be widely used. D.To make an advertisement for SPA.

4.What can be learned from the text?

A.SPA is well received in the market. B.People hesitate to pay for security.

C.SPA was sold out in the first two weeks. D.SPA is not important in life.