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) 正確答案為B。根據 Before the tour, please pay your attention to the following rules. 在游覽之前，請注意聽好以下的規定。可知，這篇講話是為了告別游客一些規定，因此B項正確。
(2) 正確答案為B。根據Bring warm clothes along, 帶上保暖的衣服；以及Wear sunglasses while watching the glaciers 的參觀冰川時戴上墨鏡，可知，游客需要帶保暖的衣服和墨鏡，因此B項正確。
(3) 正確答案為C。根據Glacier Edward 4.2 kilometers. 愛德華冰川高4.2千米。可知，C項正確。
(4) 正確答案為B。根據Waste should be taken back to the tourist center.垃圾要帶回游客中心。可推知，游覽路線沒有垃圾桶，因此B項正確。