单项选择题
A．One sixth of them are seriously polluted. B．One third of them arc seriously polluted. C．Half of them are seriously polluted. D．Most of them are seriously polluted.
A．She thinks the man should have helped earlier. B．She doesn’t need the man’s help. C．She doesn’t know the boxes are heavy. D．She wants the man to help with the boxes.
A．He will tell Mary how to operate the dishwasher. B．He will wash the dishes himself instead. C．He will help Bill to translate the manual. D．He himself will operate the dishwasher.