设矩阵则A与B（）
I'm______tograduateinthenexthalfoftheyear.
Sorrysir,wedon'thavewineorbeer.Weareonlylicensedtosell_______drinks.
Onlywhenyouhaveobtainedsufficientdata________cometoasoundconclusion.
Somemoleculesarelargeenough________(see)undertheelectronicmicroscope.
时为等价无穷小，求a,b .
