A:C2H6
B:CH4
C:C3H8
D:C3H6
先化简,再求值:6x2-(2x+1)(3x-2)+(x+3)(x-3),其中x=12.
①有点有趣____ ②来自____ ③砍倒____
④be lost____ ⑤be in great danger____ ⑥演奏乐曲____
⑦象牙制品____ ⑧好运的象征____ ⑨for a long time____