单选题：The most pressing problem any economic system faces is how

题目内容：

The most pressing problem any economic system faces is how to use its scarce resources. A．puzzling
B．difficult
C．terrifying
D．urgent

参考答案：

答案解析：

He tried to assemble his thoughts.

He tried to assemble his thoughts.A．clear B．share C．gather D．spare

分类：理工类题型：单选题

Each of the tests costs $42,500.A．Right B．Wrong C．Not mentioned

分类：理工类题型：单选题

设计具体的教学活动，引导学生完成下面的[研讨与练习]。 [研讨与练习]联系上下文，品味下列语句，并根据自己的生活体验加以阐释。 (1)我真正需要知道的一切

分类：理工类题型：单选题

Depending on where they occur, hurricanes haveA．different labels B．windows and g

分类：理工类题型：单选题

分类：理工类题型：单选题