8．What is the result of impurities in water for ice-making?

A．The water isn't able to freeze completely.

B．The quality of the ice will be affected.

C．The ice surface will be more consistent.

D．It's likely for athletes to fall on the ice.

9．Why has CO2 cooling technology been applied for the Winter Olympic Games

A．It's the most advanced technologies for ice-making.

B．CO2 is more efficient than other refrigerants.

C．CO2 is more environmentally-friendly than Freon.

D．CO2 has already existed in the atmosphere.

10．What is Gao Bo's attitude to CO2 being applied to ice-making?

A．Unclear.

B．Opposed.

C．Doubtful.

D．Favourable.

11．Which of the following is a suitable title for the text?

A．The Beijing Winter Olympic Games Is Coming.

B．Beneath Olympic Ice.

C．The Use of Refrigerants in Olympic Games.

D．The Structure of Ice.