Mark your answer on your answer sheet: A. An umbrella is being opened. B. People are eating hamburgers. C. A man is cooking on the grill. D. Some people are going on a picnic.5/6Mark your answer on your answer sheet: An umbrella is being opened. People are eating hamburgers. A man is cooking on the grill. Some people are going on a picnic.Giải thíchChọn đáp án C