—I play football on the ____/'pleɪgraʊnd/.
There are many people in Europe ________ vacation every year.
4.6×6=____ 8.9×7=____ 15.6×13=____
0.18×15=____ 0.025×14= ____ 3.06×36=____
下列关于实数a说法正确的是( )