on the first one is the second option because it says <u>estaba</u>.
on the second one is the first one because is saying <u>comimos</u>.
on the third one is the second one because it says <u>quiso</u>.
on the forth one is the second because it says <u>iba</u>.
Answer:
You only use the verb haber in the 'hay' form and never conjugate it into other forms. It stays the same with plural and singular nouns.
1. si
2. no
3. no
4. I guess it technically works but something about it sounds off.
5. no, take out the "en parte"