His name was Hansen, a common name in Norway.
A:serious
B:simple
C:usual
设a=∫0πsinx+cosxdx,则二项ax-1x5式展开式中x2项的系数是( )
①蒙辞以军中多务____
②大兄何见事之晚乎____
③朔气传金柝____
④赏赐百千强____
⑤双兔傍地走____
⑥孤岂欲卿治经为博士耶____