Present Perfect Exercise 2

Mr. Brown and Mr. Black _________________ each other for a long time.
1. have known
2. knew
Clara, how long __________ you ___________ (work) at this store?

Choose all the possible correct answers.
1. did (you) work
2. have (you) work
3. have (you) worked
The President _______________ (go) overseas twice this month.
1. went
2. has gone