021.
Hello, everyone. Welcome to Heilonggou Tourist Center! Before the tour, please pay your attention to the following rules.
1. Bring warm clothes along, because the weather is changeable.
2. Keep your safety belt fastened while you're looking at the scenery, especially the glaciers. The mountains are very high, and dangerous.
3. Wear sunglasses while watching the glaciers to protect yourselves from the strong light reflected from the ice and snow.
4. Loud cries and fireworks are forbidden near the glaciers.
5. There are many big glaciers at Heilonggou including the three major ones. Glacier Chuck is 14 kilometers high. Glacier Dean 4.8 kilometers and Glacier Edward 4.2 kilometers. The lowest point of Glacier Chuck is 3,650 meters above sea level, and is reserved for professional climbers only. During the tour, watch out for stones dropping from the mountains on the way to the glaciers, since the slopes are made up of soil and small stones.
6. No littering when you travel. Waste should be taken back to the tourist center.

答案解析：
(1) 正确答案为B。根据 Before the tour, please pay your attention to the following rules. 在游览之前，请注意听好以下的规定。可知，这篇讲话是为了告别游客一些规定，因此B项正确。
(2) 正确答案为B。根据Bring warm clothes along, 带上保暖的衣服；以及Wear sunglasses while watching the glaciers 的参观冰川时戴上墨镜，可知，游客需要带保暖的衣服和墨镜，因此B项正确。
(3) 正确答案为C。根据Glacier Edward 4.2 kilometers. 爱德华冰川高4.2千米。可知，C项正确。
(4) 正确答案为B。根据Waste should be taken back to the tourist center.垃圾要带回游客中心。可推知，游览路线没有垃圾桶，因此B项正确。