题目

 --- Some Chinese students find it difficult to understand native speakers when in London.    ---- Exactly, ______ they’ve learned a lot about grammar and known many words.       A. as if             B. as though       C. even if        D. when 答案：C如图所示，在一次夏令营活动中，小明从营地A点出发，沿北偏东60°方向走了500米到达B点，然后再沿北偏西30°方向走了500米到达目的地C点．（1）判断△ABC的形状；（2）求A、C两点之间的距离．（3）确定目的地C在营地A的什么方向．