1. It's been challenging for an industry in which most sales professionals are in their 50s.

2. On this wider view, the Nasdaq is challenging its 50-day moving average, currently 4,824.

3. This task will likely become more challenging later in the year.

4. The school is trying really hard to prevent it, but it can be a really challenging factor.

5. If you re just getting started with photography, this might be your first real challenging moment.

6. They are not challenging the law or the outcome, just the timing.

7. The company remains unique in both good and challenging ways.

8. This is just one of many lawsuits challenging the ban.

9. Power feels more challenging than where we came into the year.

10. It was challenging to balance all those pieces, but it was also our goal.

11. The trend is making it more challenging to know which certificates to trust, he said.

12. In a press release, Murphy said the month was more challenging than we expected.

13. Space films can be challenging because they can be very impersonal.

14. It is sometimes challenging to judge what the resistance is for a presenting bacteria.

15. The partnership comes at challenging times for both companies.