The People's Republic of China was ______ on October1st,1949.
A:find
B:found
C: founded
D:founding
李刚家的卫生间要铺地砖,有两种设计方案.
①第一种设计用了120块地砖,计算这个卫生间的面积____.
②第二种设计需要____块地砖?
③____种设计方案比较便宜?便宜____元?