How many words are nouns in the following sentence? "I believe that happiness is the key to success."

Choose the main verb in the sentence below: "He runs quickly to catch the bus."

What part of speech is the word "because"? "She was late because of the heavy traffic."

She sings (A) beautifully and always performs (B) profession in front of (C) large audiences (D) happily . ข้อใดผิด และควรเปลี่ยนเป็นคำใด