【单选题】

{{I}}Questions 17-20 are based on the following passage. You now have 20 seconds to read the questions 17-20.{{/I}} What is the advantage of dry ice over ordinary ice

A、It takes a longer time to melt.
B．It is lighter than ordinary ice.
C．It is cleaner to use than ordinary ice.
D．It is not so cold as ordinary ice.