单选题：There is usually a strengthened military defense system on t

题目内容：

There is usually a strengthened military defense system on the border of two countries A．boundary
B．relationship
C．edge
D．coastline

参考答案：

答案解析：

__________

分类：理工类题型：单选题

请根据以下内容回答题The World Trade Organization was foundedin 1995. It absorbed the Gene

分类：理工类题型：单选题

请根据以下内容回答题After a day' s hard work, we needsome sleep. During the sleep, the fa

分类：理工类题型：单选题

This water has been specially(pure)__________for use in cooking.

分类：理工类题型：单选题

Iregret (inform) __________ you that we are unable to offer you an employment.

分类：理工类题型：单选题