Mr. Smith gradually _____ a knowledge of the subject.
She did not take the advice that she ___ at rush hour, so she got lost.
Jasper is a great painter. He is _____ Picasso.
Men of this kind _______; we’d better ________.
--- I was trying to repair that stupid machine, but I failed. --- Well, you_______.
---What are you busy with ? --- We are carrying out a research _______ the causes of cancer.