1. have produced 2. worked 3. hasn't showed 4. started 5. has already caught
4. A. a. yet b. already c. already d. yet e. yet f. already
B. a. Banksy has already exposed his work in a museum.
b. Paul Moose Curtis has already done graffiti.
c. Paul Moose Curtis hasn't used stencil technique yet.
d. Banksy hasn't painted murals yet.
e. Bansky has already sold work yet.
