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

Part 3/ Give the correct form of the verb or the word in brackets. (2ms)
1/ It's a difficult question. I wish I ( know )    knew the answer.
2/ Would you mind ( close )                      the door?
3/ It's an exciting. I ( see )                  it twice already.
4/ Ao dai used to ( wear)                     in our school many years ago.
5/ We should practice ( speak )                       English in class regularly.