(What is said regarding) the disappearance of the (religious) knowledge and the appearance of (religious) ignorance

Narrated Anas: I will narrate to you a Hadith and none other than I will tell you about after it. I heard Allah's Messenger (sallallahu 'alaihi wa sallam) saying: From among the portents of the Hour are (the following): -1. Religious knowledge will decrease (by the death of religious learned men). -2. Religious ignorance will prevail. -3. There will be prevalence of open illegal sexual intercourse. -4. Women will increase in number and men will decrease in number so much so that fifty women will be looked after by one man.