Thus, the lip 14 a functions as a first weir for receiving the kinetic energy of rain water, thereby preventing {HEAD ~ rain water} from penetrating into {TAIL ~ the interior} of the groove portion 12 
from penetrating into
Thus , the lip 14 a functions as a first weir for receiving the kinetic energy of rain water , thereby preventing { HEAD ~ rain water } from penetrating into { TAIL ~ the interior } of the groove portion 12
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH