280÷7的商是______位数,商是______.
根据分析知:280÷7的商是两位数,280÷7=40,
故答案为:两位数,40.
Who wrote The American
A. Herman Melville B. Nathaniel HawthorneC. Henry James D. Theodore Dreiser
起重机工作级别为M3时,钢丝绳的安全系数应不小于()。
A、3.55
B、4
C、4.5
D、5