Therefore, even when the wind turbine generator is located where the wind is not always strong, {TAIL ~ the decline} of {HEAD ~ the power generation efficiency} is avoided 
Therefore , even when the wind turbine generator is located where the wind is not always strong , { TAIL ~ the decline } of { HEAD ~ the power generation efficiency } is avoided
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH