例句：
This will be a problem for some time to come.
這將是未來一段時期里的一個問題。
Researchers in this field have made some important new discoveries.
這個領域的研究人員有了一些重大的新發現。
Teachers are up against some major problems these days.
老師們最近面臨著一些重大問題。
Digital television has been around for some time now.
數字電視已經面市一段時間了。