题目

— I saw Mr. Zhou, our English teacher, in the office at seven yesterday evening. — That’s important. He    an English party with us then. A. has           B. had           C. was having      D. has had 答案：C一条质量为50kg的大蟒蛇吞吃一只小猪后，体重达到600N，被吞吃的小猪的质量是______kg．（g=10N/kg）