Statistics and logic are both challenging subjects.
出自-2011年6月听力原文
It is intellectually challenging.
出自-2010年6月听力原文
As a leader, it can be challenging to create an environment in which people will freely disagree and argue, but as the saying goes: From confrontation comes brilliance.
2015年12月四级真题（第二套）阅读 Section C
Just as it's challenging to smoke while knitting, when hands are holding needles and hooks, there's less snacking and mindless eating out of boredom.
2017年12月四级真题（第三套）阅读 Section B
These are processes that you are developing so that you are able, over time, to tackle more interesting problems, more challenging problems 一 problems that require many people instead of one person, and many skills instead of one.
2019年6月四级真题（第三套）阅读 Section B
Those who engaged in activities that were not intellectually challenging, either in a social group or alone, did not show such improvements.
2017年12月四级真题（第三套）阅读 Section B
The second rule is don't raise the stakes by challenging her authority.
出自-2011年6月阅读原文
The author's second warning is that we should avoid running a greater risk by challenging our boss's anthority
出自-2011年6月阅读原文
The STEM subjects are too challenging for students to learn.
出自-2010年12月阅读原文
Some hoped his rise to prominence would have a big impact on white Americans, too, challenging those who still harbour racist sentiments.
出自-2010年6月阅读原文
The change cut their expenditures in half, but the new living arrangement proved too challenging.
出自-2012年12月听力原文
killy then began challenging the basic theories of racing technique.
2019年6月六级真题（第一套）听力 Section B
Now, all of these problems involve significant costs for all businesses, but there're particularly challenging issues for small- and medium-sized enterprises.
2016年12月六级真题（第二套）听力 Section C
Some previous studies have suggested that challenging your brain with mentally stimulating activities might help.
2016年6月六级真题（第二套）听力 Section C
Students who take more challenging classes and spend more time studying do learn more.
2015年12月六级真题（第一套）阅读 Section C
These studies are confirming, challenging and extending what's been found using more traditional approaches.
2018年12月六级真题（第一套）阅读 Section C
We are usually tired already by the time we get on a plane, and the crowded apace and unstable Internet connection make work more challenging.
2018年12月六级真题（第一套）阅读 Section B
Adaptation to climate change is challenging.
2017年高考英语江苏卷 阅读理解 阅读D 选项
For new reporters, this can seem like a challenging task.
2017年高考英语浙江卷（6月） 阅读理解 七选五 原文
Group exercise is challenging, yet fun and empowering! of course everyone knows that exercise is good for the body.
2015年高考英语福建卷 阅读理解 阅读E 原文
It's more likely that none of us start a conversation because it's awkward and challenging, or we think it's annoying and unnecessary.
2018年高考英语全国卷2 阅读理解 阅读D 原文
Toknow magazine is a big hit in the world of children's publishing, bringing a unique combination of challenging ideas and good fun to young fans every month.
2017年高考英语北京卷 阅读理解 阅读B 原文
sit down to read and the flywheel of work-related thoughts keeps spinning一or else you're so exhausted that a challenging book's the last thing you need.
2016年考研真题（英语二）阅读理解 Section Ⅱ
Some Congress members are trying to block the plan, and at least a dozen industry groups, four states, and three environmental groups are challenging it in federal court.
2016年考研真题（英语二）阅读理解 Section Ⅱ