题目

把晒干、碾碎的土壤倒入水中，搅拌静置后，会看到沉积物分层现象。请将沙砾、沙、粉沙和黏土分别填入下图中相应的框内。 答案：从上到下：黏土、粉沙、沙、沙砾I won’t leave the classroom until my homework ______.A. finishes B. is finished C. will finish D. are finished