fix typo
diff --git a/README.md b/README.md
index 9f0cfc4..2c8f8ee 100755
--- a/README.md
+++ b/README.md
@@ -56,6 +56,7 @@
retry on next retention job.
`backup_service_period` is no longer the only fector that reflect how long
+`backup_service_period` is no longer the only factor that reflect how long
volume should backup. It’s recommended to set `backup_min_interval` and
`report_period`(see in Report part) and config a related shorter
`backup_service_period`. For example if we set `backup_min_interval` to 3600