26．Nowadays people have to pass various tests for professional __________ so that they can be qualified for a well-paid job. A．certificates B．permission C．admissionD．Perseverance
Dior was born in Normandy in 1905, and his family' s original plans for him included a career in the diplomatic service, but by the time he was twenty-three, with his parents' money, he opened a small
的展开式中所有系数之和等于729，那么这个展开式中
项的系数是( )