单项选择题A．Performance at work matters more than anything else.B．There are laws protecting employees’ working rights.C．Good reasons must be provided in order to fire workers.D．Working contracts in the US are mostly short-term ones.

单项选择题A．Drastic changes in the weather have been common since ancient times.B．The change in weather from very cold to very hot lasted over a century.C．The scientists have been studying ice to forecast the weather in the future.D．The past 10,000 years have seen minor changes in the weather.

单项选择题A．pressure from work can be reduced.B．working women can have more time at home.C．traffic and commuting problems can be solved.D．personal relationships in offices can be improved.

单项选择题A．will end all other related trade conflicts.B．is unlikely to solve the dispute once and for all.C．is linked to other trade agreements.D．is the last of its kind to be reached.

单项选择题A．oxygen.B．ancient weather.C．carbon dioxide.D．temperature.