Complete the first conditional sentences with the pairs of words in brackets.
1 If I __________ a lot, I ____________________. (study / get a degree)
2 My parents __________ if I __________ home on time. (get angry / not return)
3 There __________ a catastrophe, unless we __________ our environment. (be / protect)
4 If the weather is __________ we __________ swimming. (good / go)
5 He __________ if he _______________ anything. (get hungry / not eat)