—She____(visit) her grandparents. She usually____(visit) them on Sundays. She____(visit) them again this Sunday.
所以当x>0时, x|x| = xx =1; 当x<0时, x|x| = x−x =﹣1.现在我们可以用这个结论来解决下面问题:
People ____ ____ many trees every year.
4x-3×0.7=6.5
x=____(填小数)