"worked their arduous way up the mining valley"
"a grueling campaign"
"hard labor"
"heavy work"
"heavy going"
"spent many laborious hours on the project"
"set a punishing pace"
"his final, straining burst of speed"
"a strenuous task"
"your willingness after these six arduous days to remain here"
"the arduous work of preparing a dictionary"
Such an enterprise would be in the highest degree arduous and hazardous.
出自: Ld Macaulay
The next stage..was less arduous than he had been prepared for, and a relief from the lung-bursting strain of the ascent.
出自: J. Hilton
She found riding or pushing her bicycle uphill too arduous.
出自: M. Muggeridge