Give the correct form of the verb or the word in brackets

Give the correct form of the verb or the word in brackets
1.the car ( repair ) ... yesterday
2.He wishes that / if only he ( be ) ... a doctor
3.I (buy)...a motorbike two weeks ago
4.They (not/finish)...their work yet
5.They experienced many ( difficult ) ...but the expedition was a success
6.They failed because of their lack of ( prepare)
7.The ( explore) ... of space began in the 1960s