题目

相同质量的CO2和SO2中，含氧量之比为________。若使CO2和SO2中含氧量相同，则这两种物质的质量比为__________。 答案：16:11 11:16Ben is my friend, he is popular in his class. He can【1】(弹奏）the piano very well and is ready to teach others to learn it . He likes playing basketball very much and sometimes cheers the 【2】(运动员) of his favorite team on weekends with other fans. He thinks the 【3】(交通）is very heavy and the air is not 【4】(新鲜）any more, It’s very dirty. So he usually 【5】(骑) his bike to school, it takes him an 【6】(小时) . When it rains, he has to take the underground to school. He says if 【7】(每人）starts to do something right, the earth will be better in the 【8】(将来). However, he is not 【9】(小心的）with his school things when he is in a hurry. He always leaves homework at home on weekdays, that makes his teacher very angry . He 【10】(承诺)that he will take his homework to school next week.