"I want to emphasize our commitment to the Nigerian market,". "This new flight is a key part of Delta's African expansion and ensures that we maintain our position as the number one US carrier to Nigeria and more broadly to Africa."

VOA: standard.2009.06.13

This is what ensures that if you take 3.091, you can go on later and take 5.12.

这能确保，如果你上了本课程，你可以继续选择，5。12课程。

麻省理工公开课 - 固态化学导论课程节选

This is what ensures that if you take 3.091, you can go on later and take 5.12.

这能确保，如果你上了本课程，你可以继续选择，5。12课程。

麻省理工公开课 - 固态化学导论课程节选