(____)I don't know.
(____)Where is my pencil?
(____)Li Hua, Where's your pencil?
(____)There it is.
(____)Danny, where is my pencil? Can you see it?(你看见它了吗?)
若x=-2y=1是方程组mx+ny=1nx+my=7的解,则(m+n)(n﹣m)的值为( )
在0,|﹣1|,﹣4,﹣103这四个数中,是负整数的是____