We need to do some complex and rather difficult ...... for the project. Can you help us please?

Some people don't like to use a ...... when adding figures as they want to train their brains.

The company is about to take a ...... risk which is likely to turn into a huge profit.

If you want to calculate curves and slopes, you'd better have a look in the ...... book.

The risk we would have taken by entering the market was rather ...... which is why we did not. We'd have been blind dogs in a mine field.