下列哪个物体被托起时所用的力最接近2N [ ]
A.一头小牛
B.一块砖
C.一本物理书
D.两枚一元硬币
C
—Shall we _____ to attend the meeting _____ at the end of this month?
—Sorry, I don't know.[ ]
A. ask; holding
B. ask; to hold
C. be asked; held
D. be asked; to be held
－的相反数是_________．
