trek
n
long hard journey, esp on foot 艰辛的路程(尤指徒步的). trek, v (-kk-) [I, Ipr, Ip]
make such a journey 艰难地行走
trekking for days across the desert 行走数日穿过沙漠.
But can we blame those who looked and failed to see what Galileo saw, if we remember that to use a telescope at the limit of its powers calls for long experience and intimate familiarity with one's instrument?