29×3=69;
答:3天共用去这堆沙的69.
故答案为:69.
A.若甲、乙质量相同,则甲比乙放出的热量多.
B.若甲、乙降低的温度相同,则甲比乙放出的热量多
C.若甲、乙质量相同,初温度也相同,则甲比乙放出的热量多
D.若甲、乙质量相同,放出的热量也相同,则甲比乙降低的温度少
Drugs (毒品) have done great _____ to some people and their families. [ ]
A. harm
B. thought
C. freedom
D. favour