Government officials still have not declared the recession officially over, but the GDP report marks the second quarter of expansion after a record four quarters of decline.

VOA: standard.2010.01.29

These question marks are not the string yet right?

这些问号还不是那个字符串，对不？

哈佛公开课 - 计算机科学课程节选

These question marks are not the string yet right?

这些问号还不是那个字符串，对不？

哈佛公开课 - 计算机科学课程节选