①这套纪念币是由国家发行、强制使用的

②这套纪念币的面额和发行量是由国家规定的

③这套纪念币能够执行贮藏手段和流通手段的职能

④这套纪念币在本质上是商品

根据短文内容，选择最佳答案。

Schedule a Tour

    University of South Carolina （USC) is famous for its warm southern hospitality（好客）. Schedule a visit and feel it in person. Our walking tours are led by current students, called University Ambassadors, who are looking forward to telling you what it's like to live and study in USC. Our walking tours run Monday through Friday and most are around 2 hours. The university will be closed on Tuesday, July 4, 2017 in observance of the holiday. We welcome your visit year round and will be ready for you, rain or shine. Please refer to the list below to determine which tour is best for you and remember to book at least two weeks in advance.

“一江春水向东流”，我国许多大江大河自西向东流，其中起决定作用的因素是（    ）

读图，完整下题。