arduous

US /ˈɑːr.dʒu.əs/
UK /ˈɑːr.dʒu.əs/
"arduous" picture
1.

艰巨的, 费力的, 辛苦的

involving or requiring strenuous effort; difficult and tiring

:
The climb up the mountain was long and arduous.
爬山的过程漫长而艰巨
Learning a new language can be an arduous process.
学习一门新语言可能是一个艰巨的过程。