例句：
Certain of those present were unwilling to discuss the matter further.
某些在場(chǎng)的人不愿意進(jìn)一步討論這個(gè)問(wèn)題。
Those beliefs still prevail among certain social groups.
這些信念在某些社會(huì)群體中仍很盛行。
The work must be completed within a certain time limit.
這項(xiàng)工作必須在一定期限內(nèi)完成。
The company's financial position is not certain.
這家公司的財(cái)務(wù)狀況不明朗。
Many animals breed only at certain times of the year.
很多動(dòng)物只在一年的某個(gè)時(shí)候繁殖。