单项选择题
The speaker thinks that（）
A．car causes pollution only in some cities. B．60% of the cities are affected by car pollution. C．90% of the city residents suffer from car pollution. D．car is the main contributing factor in polluting air.
单项选择题 Who among the following owns a soccer team（）
单项选择题 Who among the following is a biographer（）
单项选择题 Which person carried out research in the Amazon region（）
