冰的密度为0.9×10³kg/m³，一体积为0.2m³的冰块全部熔化成水，水的体积为____m³

下列是关于生物化石研究的相关结论，正确的是 （　　）

    Lucy and Lily are twins . They are 13 years old . They look the same . But they have different hobbies . Lucy likes collecting stamps . She has many beautiful stamps . They're from different cities and countries . But Lily likes growing flowers . The flowers are all very beautiful . Lucy and Lily both like reading books . Lucy likes reading storybooks . But Lily likes reading science books . On Sunday , they usually ride bikes to the park . They can play with their friends there . Sometimes their parents go there , too .

陶行知的“捧着一颗心来、不带半根草去”，能使我们深刻感受到（    ）