SELECT count(distinct c) as nb FROM t_asv where b = 66 group by b
1 And the fifth angel sounded, and I saw a star from heaven fallen unto the earth: and there was given to him the key of the pit of the abyss. 2 And he opened the pit of the abyss; and there went up a smoke out of the pit, as the smoke of a great furnace; and the sun and the air were darkened by reason of the smoke of the pit. 3 And out of the smoke came forth locusts upon the earth; and power was given them, as the scorpions of the earth have power. 4 And it was said unto them that they should not hurt the grass of the earth, neither any green thing, neither any tree, but only such men as have not the seal of God on their foreheads. 5 And it was given them that they should not kill them, but that they should be tormented five months: and their torment was as the torment of a scorpion, when it striketh a man. 6 And in those days men shall seek death, and shall in no wise find it; and they shall desire to die, and death fleeth from them. 7 And the shapes of the locusts were like unto horses prepared for war; and upon their heads as it were crowns like unto gold, and their faces were as men's faces. 8 And they had hair as the hair of women, and their teeth were as `teeth' of lions. 9 And they had breastplates, as it were breastplates of iron; and the sound of their wings was as the sound of chariots, of many horses rushing to war. 10 And they have tails like unto scorpions, and stings; and in their tails is their power to hurt men five months. 11 They have over them as king the angel of the abyss: his name in Hebrew is Abaddon, and in the Greek `tongue' he hath the name Apollyon. 12 The first Woe is past: behold, there come yet two Woes hereafter. 13 And the sixth angel sounded, and I heard a voice from the horns of the golden altar which is before God, 14 one saying to the sixth angel that had one trumpet, Loose the four angels that are bound at the great river Euphrates. 15 And the four angels were loosed, that had been prepared for the hour and day and month and year, that they should kill the third part of men. 16 And the number of the armies of the horsemen was twice ten thousand times ten thousand: I heard the number of them. 17 And thus I saw the horses in the vision, and them that sat on them, having breastplates `as' of fire and of hyacinth and of brimstone: and the heads of lions; and out of their mouths proceedeth fire and smoke and brimstone. 18 By these three plagues was the third part of men killed, by the fire and the smoke and the brimstone, which proceeded out of their mouths. 19 For the power of the horses is in their mouth, and in their tails: for their tails are like unto serpents, and have heads; and with them they hurt. 20 And the rest of mankind, who were not killed with these plagues, repented not of the works of their hands, that they should not worship demons, and the idols of gold, and of silver, and of brass, and of stone, and of wood; which can neither see, nor hear, nor walk: 21 and they repented not of their murders, nor of their sorceries, nor of their fornication, nor of their thefts.