A:finally
B:officially
C:frequently
D:gradually
How ____(sad) she was telling me that he lost another bike!
已知向量a→=(2,1)b→=(x,-6),若a→⊥b→,则|a→+b→|=( )
下列划线字的注音全都正确的一项是( )
( )
①积极的暗示,增强信心 ②立志做大事,不做小事
③塑造新形象,激励斗志 ④实践中锻炼,激活能力