A．plannedB．leveledC．enlargedD．constructedMore than 89 o……

单项选择题Native American artwork and artifacts have been enthusiastically collected and studied abroad for a number of years.

单项选择题All gases and most liquids and solids expand when heated, but they do not expand equally.

单项选择题The Industrial Revolution marked the beginning of an epoch of exodus from rural areas to cities.

单项选择题City dwellers are exhilarated by country air.

单项选择题Enamel, the hardest substance in a human being’s body, covers the entire crown of the tooth.