例句：
This will be a problem for some time to come.
這將是未來(lái)一段時(shí)期里的一個(gè)問(wèn)題。
Researchers in this field have made some important new discoveries.
這個(gè)領(lǐng)域的研究人員有了一些重大的新發(fā)現(xiàn)。
Teachers are up against some major problems these days.
老師們最近面臨著一些重大問(wèn)題。
Digital television has been around for some time now.
數(shù)字電視已經(jīng)面市一段時(shí)間了。