1000x−1000(1+25
南宋在中国古代史上存在的时间段为( )
If you are hunting ________ chance to improve yourself in English,I think the English corner will be ________ smart choice.( )
设O点在△ABC内部,且有 OA→+2OB→+3OC→=0→ ,则△ABC的面积与△AOC的面积的比值为____.