There are about 80,000,000 mines*  under the ground in more . than 60 countries. It is difficult and dangerous to clear these rnines, About 50  people including many children were’ killed ‘or htirt each iay.  In 2003,  APOPO,  a Dutch research com pan y that uains the an imals, came up with the-idea of s\ng rats to search for the mines.
The animal trainers ‘found that a kind of rats from Africa were clever and had.a sharp*  sense of smell.  The rats were about 75 cm long and.weighed about l.35 kg, light enough to run across a minefield without setting off the mines.
In January 2004, the APOPO started this project. First, the trainers let the 4-week-old baby rats get familiar with humans. A few weeks later, the rats were no Ionger afraid of people and ‘the things around them. Then they were trained to connect a click* sound with food. After the rats had leamed that, the trainers then taught them to tell the difference between the smell of mines and other smells. When the rats could do it, the click was sounded and they were given a bit of banana.  The method was called clicker training. “The training isn’t easy, said trainer Abdullah Mchomvu.  “You have to be patient. Sometimes I get angry, but then again, I tell myself these are animals.”
After nine months’training, the rats were taken to a minefield. They’ran across the minefield, stopped, sat and scratched the ground to tell the deminers*  that they smelt out’a mine.  Then the mine was cleared. It had  taken two ‘deminers  a day to clear a 200㎡ . minefield, but with the help of two rats ‘they could finish it in two hours.
The rats and the deminers saved thousands of lives, “The rats did this job much better than we expected. So far they have helped to make almost 2,000,000㎡ of land safe. They are heroes,” said Bart Weeqens, the head of the APOPO.
The APOPO trained the rats to search for     .

A．children

B．animals

C．mines

D．bananas

While training the rats, the trainers have to be

A．patient

B．clever

C．brave

D．serious

How long did the training last?

A．Two hours.

B．One day.

C．Four weeks.

D．Nine months.

Which of the following is NOT TRUE according to the passage?

A．Each day about 200 people were killed or hurt by mines,

B．The APOPO started to train the rats in January 2004.

C．The trainers gave the rats food after they smelt out a mine.

D．The rats and the deminers saved thousands of lives.