{HEAD ~ The slider} includes: a first cylindrical portion having an upstream through {TAIL ~ hole} penetrating therethrough; a second cylindrical portion having a downstream through hole penetrating therethrough and communicating with the upstream through hole; and a semipermeable membrane closing the upstream through hole 
{ HEAD ~ The slider } includes : a first cylindrical portion having an upstream through { TAIL ~ hole } penetrating therethrough ; a second cylindrical portion having a downstream through hole penetrating therethrough and communicating with the upstream through hole ; and a semipermeable membrane closing the upstream through hole
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH