1.Becauseoftherain,we____domorningexercises.
A.needn'ttoB.mustn'tC.don'tneedtoD.needto
2.Mymotherwastiredlastnight,soI___forher.
A.ateupB.washedupC.cleanedoverD.washedover
3.Hedidn'tstudyhard.Asaresult,he_____(notpass)thedinalexam.
4.Scientists__havedeveloped__(develop)differentkindsofrobotsinthepastfewyears.