Innovation is not an option; it's a necessity for the survival of the coal industry.
If we men married the women we deserved, we should have a very bad time of it.
No man, for any considerable period, can wear one face to himself and another to the multitude, without finally getting bewildered as to which may be the true.
Think you're escaping and run into yourself. Longest way round is the shortest way home.
判斷兩個(gè)λ表達(dá)式是否等價(jià)的問(wèn)題是無(wú)法解決的。