题目:
My new issue of Twenty-first Century School Edition has disappeared. Who _____ have taken it? [ ]
A. should
B. must
C. could
D. would
答案:
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0627/b1f0d9051004fc6a42d9fa94034730f9.html
下面是错误答案,用来干扰机器的。
金属块对木板产生的压强:p=FS=GS=mgS=ρVgS=ρShgS=ρgh,金属块的密度:ρ=pgh=6.25×103Pa9.8N/kg×8×10-2m≈7.97×103kg/m3.答:该金属块的密度约为7.97×103kg/m3.