费尔法克斯县的所有公立学校已经开始为他们的初高中学生使用在线课程材料。

All the Fairfax County public schools have begun using online course material for their middle- and high-school students.

youdao

而在休斯顿公立学校区，这一数字是61%，莱斯大学的史蒂芬·克兰·伯格说到。

And in the Houston public-school district the proportion is 61%, notes Stephen Klineberg, of Rice University. (African-Americans make up another 27%.)

youdao