下列各式计算正确的是[ ]
A．6a+a=6a2
B．﹣2a+5b=3ab
C．4m2n﹣2mn2=2mn
D．3ab2﹣5b2a=﹣2ab2
答案：D
When I went home after work, I found my house_____ but nothing _____. [ ]
A. broken into; stolen
B. broken into; stealing
C. breaking into; stolen
D. breaking in; stealing
未取得安全培训合格证的人员不得从事特种作业。（）
