在弗吉尼亚理工大学的土木工程师马克·爱德华兹说，大多数学区因为铅治理的费用而不检测他们的饮用水。
Most school districts do not test their water because of the costs associated with lead remediation, said Marc Edwards, a civil engineer at Virginia Tech.
全国超过15000个学区出现了不同的科学和数学教学方法。
Throughout the nation's more than 15,000 school districts, widely differing approaches to teaching science and math have emerged.
他们一直是学区高等数学项目的大力支持者。该项目本来是从四年级开始，但现在将从六年级开始。
They have been huge supporters of the district's advanced mathematics program, which once began in the fourth grade but will now start in the sixth.
应用推荐