单项选择题
Physicists have made new discoveries that： challenge our （）theories of the universe.
A.organized B.existed C.adapted D.established
单项选择题 Afteranumberofdisagreementswiththecommittee，thechairmandecidedto（）.
单项选择题 Itisreportedthatthereisnobetter（）formother’smilk.
单项选择题 Theclassneedsamonitor（）.
