uphill
adj. 艰难的，费力的；=difficult；hard; tough; demanding
Whenever the Chinese national football team plays a European team, it is going to be an uphill struggle.
Alibaba has been widely regarded as an e-commerce giant. Although it seemed like an uphill task for pinduoduo to stand out, it dealt tactfully with the hard realities and went public merely three years after its launch.
Gender parity in science is an uphill struggle.
We have got the toughest part done, and it will be downhill all the way from here.
翻译：It is an uphill task to anyone who needs to improve their IELTS score from 6 to 8 within two months.
参考：To improve IELTS from Band 6 to Band 8 within two months is an uphill struggle/task to anyone.
造句：It is an uphill battle to defeat depression.
downhill
adj. 形容做某事易如反掌
be downhill all the way (from here)
We have got the toughest part done, and it will be downhill all the way from here.
adv. "情况每况愈下地”
get worse, become worse, worsen, deteriorate, go from bad to worse=go downhill=slide downhill=head downhill
It has been a tough year for many companies. Many went downhill before going bankrupt.
The economy of the northeastern provinces has headed downhill in recent years.
Some celebrity couples seemed to have an enviable marriage, but their relationship slided downhill and ended in divorce.
翻译：Things go downhill. We have to do something to deal with it.
参考：Things are going downhill. We have to do something about it.
造句：A good marriage needs to be carefully managed since intimate relationships head downhill easily without understanding and love.