Complete the sentences with is, am or are: a. butterflies ___ beautiful. b. I ___ happy. c. The bus ___ late again. d. He ___ an astronaut. e. It ___ cold today. f. You ___ a great student. g. They ___ good friends. h. We ___ very hungry. i. She ___ my sister. j. I ___ a doctor.

Here are the completed sentences: a. butterflies are beautiful. b. I am happy. c. The bus is late again. d. He is an astronaut. e. It is cold today. f. You are a great student. g. They are good friends. h. We are very hungry. i. She is my sister. j. I am a doctor. **Explanation:** * **is** is used for singular nouns (the bus, he, it, she) and singular pronouns. * **am** is used only with the pronoun 'I'. * **are** is used for plural nouns (butterflies, they) and the pronouns 'you' and 'we'.