比一比,再组词。
并____ 中____ 傲____ 窜____
饼____ 忠____ 熬____ 串____
如果复数2+ai1+2i的实部和虚部互为相反数,那么实数a等于 ( )
CH3CH2C(CH3)2C(CH2CH3)2CH3.
(I)证明:BC⊥AB1;
(II)若OC=OA,求直线CD与平面ABC所成角.
- What do you often have for breakfast?
- I often have _________ egg and some milk.