读拼音,写词语。
shǐ jìn
shǒu qiǎo
ní rén
zán men
____
With the help of computers, people will find it easier to keep the traffic smoothly.
如图,四边形ABCD是⊙O的内接正方形,若正方形的面积等于4,则⊙O的面积等于 ____.