A Mexican teacher has been honoured after a video showed her calming pupils as a gun battle raged（肆虐）outside her school.
   Martha Rivera Alanis was presented with a certificate （證書） on Monday to recognise her bravery in ordering her class of five-and six-year-old children to lie on the floor of their classroom，before attempting to calm them by leading a chorus （合唱） of a song from television show Barney & Friends.
   Rivera Alanis filmed some of the scenes from inside the classroom in Monterrey一the sound of gunfire can be clearly heard 一and posted the resulting video on Twjye.aiter.It was picked up and quickly，spread around the Internet，with the 33-year-old teacher earning the admiration of many. "Of course，I was afraid，but my kids got me through it，" Rivera Alanis said.
   The video shows Rivera Alanis's 15 young pupils lying face down on the floor. "No，my love，nothing is going to happen，just put your little face on the floor，" Rivera Alanis is heard telling one worried girl，before loud bursts of gunfire can be heard.
   In the video，Rivera Alanis attempts to distract the children by leading them in a song from Barney & Friends. "If the rain drops were chocolate，I would love to be there，opening my mouth to taste them，" the class sang as they lay on the floor.
   "My only thought was to take their minds of that noise，" Rivera Alanis said. "So I thought of that song."
   Rivera Alanis's school and those in several Mexican cities hit by drug violence have held emergency drills （應(yīng)急演練） in the past to instruct teachers and students what to do in case of gunfire.Drug-related violence is said to have killed more than 35，000 people in Mexico over the past four years.
   "We do drills constantly （經(jīng)常地），because the area where we are is a high-risk zone，" Rivera Alanis said，adding that the children "behaved in the way we had practised".

（1）Why was Martha Rivera Alanis given a certificate？（ no more than 12 words ）

Because she was brave in ordering her class in a gun battle.

Because she was brave in ordering her class in a gun battle.

（2）Where did Martha post the video？ （ no more than 6 words ）

She posted the video on Twitter.

She posted the video on Twitter.

（3）What can be heard in the video？ （ no more than 18 words ）

Martha's calming her pupil，Martha and her pupils' song，and loud bursts of gunfire can be heard.

Martha's calming her pupil，Martha and her pupils' song，and loud bursts of gunfire can be heard.

（4）What has been held in the past to instruct teachers and students what to do in case of gunfire？（ no more than 5 words ）

Emergency drills have been held.

Emergency drills have been held.

（5）What do you think of Martha Rivera Alanis？ （ no more than 20 words ）

She is a kind and clever teacher who takes good care of her students.

She is a kind and clever teacher who takes good care of her students.