A、It’s cheaper to make a landmine than to remove it. B、To place a landmine is more difficult than to produce it. C、It’s easy to

Heidi Kuhn lives in the San Francisco Bay area in California. She decided to do something special with her life after she was successfully treated for cancer. (26) In 1997 ,she started an organization to continue Princess Diana’s work to rid the world of landmines. Roots of Peace does more than help clear landmines. It also works to return the land to agricultural use. Heidi Kuhn says landmines must be removed from the earth just as cancer is removed from the body.
    (27) Roots of Peace says a landmine costs anywhere from three to thirty dollars to produce and place in the ground. But the cost to remove one of the bombs is about one thousand dollars. Metal detectors cannot be used in many cases because landmines can be made of non-metal materials.
    (28) Dogs that are specially trained to smell landmines can be used to map out minefields. In some cases, remote-controlled machines are used to remove the bombs. But in other cases,the mines must be carefully dug out by hand. (29) Roots of Peace supports the planting of native crops and the employment of landmine victims to farm the cleared land.
    Heidi Kuhn says," Being a cancer survivor, there’s no real cure to cancer. There’s no real cure to AIDS. But there is a cure to the landmine issue,and that is removal. So this is something that is tangible. And as we remove the seeds of hostility from the ground,the seeds of terror,and plant agricultural alternatives so that peace and prosperity may lead the next generation forward. "
26. What did Heidi Kuhn do after she recovered from cancer?
27. What can we learn about landmines?
28. What does the organization train dogs to do?
29. What does the organization Roots of Peace do after removing the landmines?