retentive
/rɪˈtentɪv; rɪ`tɛntɪv/ adj
1 (of the memory) having the ability to remember facts, impressions, etc （指记忆力）有记性的, 记忆力强的.
2 having the ability to hold or contain liquid, etc 能保持或容纳液体等的
retentive soil, ie that does not dry out quickly 能保持水分的土壤.