Join the pairs of sentences together by using given connections: I was busy all day. I couldn’t go to the football match. (so)

IV. Join the pairs of sentences together by using given connections
1. I was busy all day. I couldn’t go to the football match. (so)
=>____________________________________________________________
2. I’m tired. I stayed up late watching TV. (because)
=>____________________________________________________________
3. Hoa failed her math test. She has to do the test again. (therefore)
=>____________________________________________________________
4. She is very tired. She has to finish her homework before she goes to bed. (however)
=>____________________________________________________________