{By these three plagues} (apo t(936e) tri(936e) pl(8867)(936e) tout(936e)).
Our "plague" or stroke from pl(8873)s(935c), as in  Lu 10:30  and often
in Rev. ( 9:20  11:6  15:1,6,8  16:9  18:4,8  22:18 ). It is used
in  Ex 11:1ff.  for the plagues in Egypt. The three plagues here
are the fire, smoke, and brimstone which proceed from the mouths
of the horses. {Was killed} (apektanth(8873)an). First aorist
passive indicative of apoktein(935c), to kill, third person plural,
though 	o triton is neuter singular because a collective idea.
See same form in verse  20 .