藏地民谚有“汉家饭果腹，藏家茶饱肚”之说。据有关专家研究表明，茶叶中所含的咖啡因、儿茶素等成分，有明显降低血脂、预防心肌梗死、脑血管梗阻的作用。回答第问题。
如此奢爱茶叶的藏地却不生产茶叶，主要原因是（   ）

下列明清时期的历史现象中，最能体现当时世界发展趋势的是（    ）

△×△ ＝25     □＋□＋□＝24     ☆× □＝32

△＝____      □＝____     ☆＝____

△＋☆＋□＝____

    An English traveler found himself in Norway with only enough money to buy the ticket for him to go back home. As he knew that it would take him only two days to get to England， he decided that he could easily spend the time without food. So he bought a ticket and got on the ship. The man closed his ears to the sound of the lunch bell. When dinnertime came， he didn't go to dinning room， saying that he was not feeling very well.

    The next morning he still didn't have breakfast and at lunchtime he again stayed in his room. But at dinnertime he was so hungry that he went to the dinning room and ate everything the waiter put in front of him. He got ready for the quarrel(争执).

    “Bring me the bill，” he said. “The bill， sir?” said the waiter in surprise. “There isn't any bill. On our ship meals are included (包括) in the money for the ticket，” said the waiter.

①学习只有痛苦没有快乐，不如放弃

②要学会自主学习，提高学习效率

③与生命发展同步，人有学习的天性

④学习虽然是辛苦的，但成功以后可以得到一种超越自我的快乐