题干
The 2010 World Expo ________ in Shanghai successfully. It was an honor of all
of the Asians.
of the Asians.
A：is held
B：was held
C：has been held
D：would be held
答案(点此获取答案解析）
B
的三个内角
所对边的长分别为
，设向量
．若
，则角
的大小为（ ）
