题目

一个铜球的质量是178g，体积是0.05dm3，则这个铜球空心部分的体积是_____cm3（铜的密度是8.9x103kg/m3）。 答案：【答案】30cm3【解析】根据求出178g铜的体积，然后用铜球的体积减去铜的体积即为空心部分的体积。由可得，178g铜的体积：，铜球的体积V球=0.05dm3=50cm3，则空心部分的体积：V空=V球-V铜=50cm3-20cm3=30cm3。根据句意及首字母提示，补全单词。 1. January comes after D_______. 2. Difficult m_______ hard. They have the same meaning. 3. —How do you c_______ your birthday every year?     —I often have a birthday party. 4.Kangkang often helps his mother do some c_______ on Sundays. 5. —Did you recite a Chinese p_______ at the party?     —Yes, I recited one of Li Bai's.