单项选择题 场景中进行喷锚加固支护该隧道施工时，喷射混凝土封闭开挖面应采用早强混凝土，喷射厚度宜为（）。

问答题 In a lottery a person may win a million dollars or more. What would be the advantages of winning a million dollars’? Would there be disadvantages? You should write a composition of no fewer than 120 words on the subject on the Answer Sheet.

单项选择题 北京市中关村科技园区的首要区位优势是（ ）