This one is tricky for even the most seasoned marketers, and here's why: most measurements focus on numbers, not on effect. (lawyerist.com)
This question is tricky because it gives you lots of numbers and letters and it's not entirely clear what you're supposed to do with them. (businessinsider.com)
Changing sex is a tricky business for humans, involving hormone injections and surgery, but some animals make it look easy. (newscientist.com)