单项选择题
A．avoid confusion in fishing activity B．avoid unneeded effort in fish sound studies C．detect enemy submarines D．pick up new sounds
A．Her writings. B．Her parent’s letters. C．Her children. D．Her school records.
A．He simply reports the disease objectively. B．He is worried about the spread of the disease. C．He is disappointed at the tests of the London doctors. D．He believes that the disease will soon be controlle