单项选择题
A．tell the origin of intelligence tests B．explain the basic principle of intelligence tests C．describe the changes in the content of intelligence tests D．state the development of intelligence tests
A．Aluminium. B．Silver. C．Milk. D．Mineral water.
A．a material that can be seen through B．a translucent(半透明的) material C．a material that can not be seen through D．a lucent material