When was the Paleozoic era? When was the Ogallala Aquifer formed? Is ocean acidification natural? When did the Devonian period end? When does the Antarctic Treaty expire? When was the theory of plate tectonics accepted? When was the last major ice age?
根据第一段When there are too many visitors,the quality of life for the local community can be affected,the surrounding natural environment can become worse,and the quality of the tourists' experience can fall.(当游客太多时,当地社区的生活质量会受到影响,周围的自然环境会变得更糟,游客的...
Antarctica is the only continent on Earth without a native human population. ... Since no country owns Antarctica,no visa is required to travel there. If you are a citizen of a country that is a signatory of the Antarctic Treaty, you do need to get permission to travel to Antarctica. Wh...
B 【解析】 由by the end of last year可知,应该用过去完成时。 —Why does Jane feel so upset? —She failed the exam and she has no friends ___. A. talking B. talking with C. to talk D. to talk with D 【解析】 此题考查动词不定式做定语来修饰名词,常放在名词的后面。题干的含义是...
it is full of wildlife like the famous penguins, that can adapt to its hard conditions. It was not until 1895 the Norwegian explorer called Carstens Borchgrevink set his foot on the Antarctic mainland. In 1961, 12 countries sign a treaty to make it the world's biggest nature reserve. Tod...