Lisa Pina never thought she would need the fire safety training she received during her apprenticeship (学徒期) as a union painter and dry waller. On Friday morning，she was thanking God she had it.
On Thursday night，while Pina was babysitting her granddaughter，nephew and two nieces in her sister’s apartment，she smelled smoke and realized the apartment building was on fire. When her 4­year­old granddaughter Ilean Garcia began saying，“We’re going to die，”she knew she had to act.Pina,39，first sealed the door，and then told all four children to get on the floor. After calling 911，she told the children to start singing and promised them all treats as soon as they reached safety. “I said，‘OK，we’re going to lie down and we’re all going to play a game，’” Pina said. “We all started singing our ABCs and 123s.I was just trying to make it fun.” Pina patiently waited，and a few minutes later，Riverside County sheriff’s deputies (治安官的助手) arrived. Pina，Ilean,8­year­old Gabriel Parga,5­year­old Aubreyana Parga and 4­year­old Meriyah Parga were all trapped on the second floor as flames filled the first story.  Pina did the only thing she could. She opened the window and dropped the children，one­by­one，into the arms of the sheriff’s deputies about 15 to 20 feet below. “I just needed to keep the kids calm so they wouldn’t be afraid，”Pina said.“I was deathly afraid inside，but I couldn’t let them know that.”[Not long after dropping the children out of the window，firefighters arrived with a ladder and rescued her. Ten people were treated at the scene for suffering smoke，but nobody was seriously injured.
The text is mainly about________.

A．a big fire without serious injury

B．an urgent call 911

C．a brave babysitter

D．a babysitter rescuing kids from a big fire

The underlined word “it” in Paragraph 1 refers to________.

A．a union painter

B．a dry waller

C．the fire safety training

D．the apprenticeship

Before Lisa Pina called 911，in order to prevent the fire，she________.

A．let children get on the floor

B．opened the windows of the second floor

C．closed the door hard

D．had children start singing

According to the text，we know that________.

A．Lisa Pina was the last one to be rescued

B．the fire didn’t cause any injury

C．the children were sent to hospital after the fire

D．during the fire Lisa Pina wasn’t afraid at all