What does "for" mean in this sentence? The sentence is : "Computed values match well to observed values in summer, for low flow rates and recession periods." I know the meaning of first half of the sentence,the time is "summer".However,"for" in the second half puzzles me. Does the "for" mean : (1) "because" .That is to say,because flow rates are low in summer and there're recession periods in summmer,so computed values match well. (2) "and" .That is to say,computed values match well in three situations:summer,days when flow rates are low and recession periods. Which one is right,or they are all wrong?