Find the variant that are not correct.
1. He...have made a mistake.
a) must b)a walk c) walking d) they walk

2. They suggested ... in the park.
a) to walk b) a walk c) walking d) they walk

3. She saw the man ... the purse.
a) took b) taking c) take d) who had taken

4. They ... go to London on holidays.
a) can b) will c) may d) should to

5. ... an honest man.
a) He is believed to be
b) It is believed that he is
c) They say that he is
d) He believes to be

6. He will ... to solve the problem.
a) be able b) have c) could d) might