在○里填上“+”、“一”或“×”。3○3=69○7=25○5=257○6=133

搜题请搜索小程序“爱下问搜题”

问题填空题

在○里填上“+”、“一”或“×”。

答案

+；-；×；+；×；×

选择题

--Tony, come down and help me with the heavy box!

-- Come on! I _____ all day long．Get Peter to do that!

A．work

B．had been working

C．had worked

D．have been working

解答题

20-19+18-17+16-15+…+2-1=______．