Find and correct the mistakes in the following sentences.
1. I forgot have discussed this topic with you.
2. Had won many maths competitions helped me win a place at university.
3. Nam regretted not having choose a more interesting Course at university.
4. He was proud of had won the first place at the biology competition.
1. have -> having
2. had -> having
3. choose -> chosen
4. had -> having
1: have
=>having
2: had
=>having
3: choose
=>chosen
4: had
=>having