28×29+29×2=29×28×2
已知a→=(1-t,1-t,t),b→=(2,t,t),则a→-b→的最小值为 ( )
A. carrots B. milk C. sandwich D. beef E. delicious
Hi, I' m Mary. My favourite food is a ____. It's ____.I don't like____but chicken is OK. My favourite vegetables are ____.I like ____very much.
一根电线长20米,第一次剪去3.8米,第二次剪去4.15米,这根电线和原来相比,短了( )米.