一船在A处测得北偏东45°方向有一灯塔B，船向正东方向以每小时20海里的速度航行1.5小时到达C处时，又观测到灯塔B在北偏东15°方向上，求此时航船与灯塔相距多少海里?

群贤毕至，____。                      （王羲之《兰亭集序》）

下列各组二次根式中，可化为同类二次根式的是(     )

    Once there were two mice. They were friends. One mouse lived in the country; the other mouse lived in the city. After many years the Country mouse saw the City mouse; he said, "Do come and see me at my house in the country." So the City mouse went. The City mouse said, "This food is not good, and your house is not good. Why do you live in a hole in the field? You should come and live in the city. You would live in a nice house made of stone. You would have nice food to eat. You must come and see me at my house in the city."

    The Country mouse went to the house of the City mouse. It was a very good house. Nice food was set ready for them to eat. But just as they began to eat they heard a great noise. The City mouse cried, " Run! Run! The cat is coming!" They ran away quickly and hid.

    After some time they came out. When they came out, the Country mouse said, "I do not like living in the city. I like living in my hole in the field. For it is nicer to be poor and happy, than to be rich and afraid."

作文。
        温暖是掌心里的一缕阳光。温暖是寂寞时的一句问候，是无助时的一个拥抱，是沮丧时的一声鼓励，是困难时的一次援助……有温暖，生命就有希望；有温暖，一路才有快乐相随。
         请以“有这样一种温暖”为题目，写一篇作文。
         要求：①要有真情实感，语言通畅。
                     ②文中不得出现真实的地名、校名、人名。
                    ③字数：600字。