单项选择题
A．are yet to be proved B．are to be further studied C．are supported by scientific evidence D．are self-evident
A．their English is not good enough B．they are afraid they might meet with unfair judgment in these areas C．there is a wide difference between Asian and Western cultures D．they know little about American culture and society
A．take care not to be over-critical in his writing B．watch carefully to see that nobody else takes his job C．be careful to ensure that his comments retain their value D．be sure that his salary keeps pace with inflation