六、任务型阅读。
阅读短文，回答下列问题。
Tourism is causing damage(损坏)to many cultural relics(遗迹). To better protect them, grotto(洞穴)temple workers have been asked to do research and decide how many daily visitors they can safely receive.
Causes of the damage
Tourists' poor behaviour, like dropping litter around, can lead to problems and damage relics.
Over many centuries, the ancient rocks that make up these grottoes slowly corrode(侵蚀)because of the acidic(酸性的)content of air, water and microorganisms(微生物). But when they are open to the public, the corrosion process speeds up.
According to a study by the China University of Geosciences, the carbon dioxide(二氧化碳)that visitors breathe out has made the air more acidic at the Longmen Grottoes. At the Mogao Grottoes in Gansu, researchers found that visitors often bring in microorganisms. Even their body heat can increase the caves' temperature. All of these things can harm the relics inside.
Online tours offer the other choice
To keep a balance between protecting relics and educating the public, some grotto sites have created their own digital(数字化的)museums.
The Mogao Grottoes in Dunhuang, Gansu
If you want to see the beautiful statues and paintings of the Mogao Grottoes, just go to e-dunhuang.com. You can learn all about the stories behind the relics with this “virtual(虚拟的)tour guide”.
The Maiji Mountain Grottoes in Tianshui, Gansu
Visit mjssk.cn and you'll not only get travel information about the Maiji Mountain Grottoes but also collect pictures from the site. There are also descriptions of important works of art.
1. Why does grotto rock corrosion speed up?
Because the grottoes are open to the public.
2. What does mjssk.cn offer to grotto visitors?
Travel information, pictures from the site and descriptions of important works of art.
3. What do you think of online grotto tours?
They help keep relics safe. /They are easy but not as fun. (言之有理即可)
