⑴____ A. book B. good C. food D. classroom
⑵____ A. pens B. teachers C. apples D. cats
⑶____ A. like B. history C. Friday D. time
⑷____ A. decision B. station C. attention D. pollution
⑸____ A. happy B. family C. what D can
下列各式计算中,结果正确的是( )
地球仪上的东经度是指 ( )
面积是____cm2.
下列做法,符合因地制宜、可持续发展的是
如图,⊙O是正五边形ABCDE的外接圆,这个正五边形的边长为a,半径为R,边心距为r,则下列关系式错误的是( )