ascertain /ˌæsəˈtein/ vt. 查明，弄清，确定：ascertain the truth (true situation) 查明真相(真实情况)；ascertain where the trouble lies 弄清毛病所在 I ascertained that he was dead. 我查明他已死了。［考句］We shall probably never be able to ascertain the exact nature of these sub-atomic particles.我们可能永远不能确定亚原子的实质。