Question 1: Open

Question 2: Purchase

Question 3: Jumping off a building

Question 4: Bicycles/Bicycles

Question 5: Deal.

The school library is open from 9 am to 6 pm from Monday to Friday. Combined with the context and Chinese hints, we can see that the adjective open is a predicative.

I often buy presents for my parents on their birthdays. According to the context, this sentence describes an objective action, so we use the simple present tense. The subject I is the singular first person, so the predicate verb uses the prototype. According to the Chinese prompt, you can fill in the prototype verbs buy, buy.

All the children jumped for joy when they heard the good news. According to the context, this sentence describes the action that happened in the past, so it uses the general past tense. According to the Chinese prompt, we can know the verbs jumped and jumped to fill in the past tense.

Question 4: Where are you going to put your bike? It is too crowded here. Combining the context and Chinese prompts, we can know to fill in the singular or plural nouns bike(s)/bicycle(s) as the object.

Some teenagers don't know how to deal with their personal problems. They often go to therapy. In this sentence, to is an infinitive symbol, and the verb behind it uses the prototype. According to the Chinese prompt, we can know how to fill in the prototype verb deal.