题目

Kamal Meattle, in New Delhi, India, grows 400 plants in his office building’s greenhouse to help clean its indoor air. On the roof of an office building in India’s capital, the world’s smoggest city, Kamal Meattle has a special way of cleaning the air: a greenhouse with 400 common plants. Meattle has 800 other plants spread throughout its lower six floors, greening each room and hallway. Their job: remove harmful things from the outdoor air. Meattle uses rainwater to water the trees so that they can grow faster and take in more pollutants. He’s asking India’s new government to re小明按图所示甲→乙→丙的顺序进行实验，测得石块的体积为2020cm3，质量为5454g，求得石块的密度为2.72.7g/cm3．他测得的石块密度偏大还是偏小：偏大偏大，因为测质量时，石块上沾有水，而且还系着线，测出的质量会偏大测质量时，石块上沾有水，而且还系着线，测出的质量会偏大．较准确测量的顺序应该为：丙→甲→乙丙→甲→乙．