__ the difficult maths problem, I have consulted Professor Russell several times.

What a beautiful dress you are wearing today!—________. It’s nice of you to say so.

My computer has a virus. I asked my friend to take a look at it. She can _____ any computer problems. [ ]

Did you see a child dressed in red pass by?—-Sorry, I _____ the poster on the board without noticing anyone

new graduate, he doesn’tknow_______it takes to start a business here