物质的下列性质中,属于化学性质的是( )
已知a→=(2,1),b→=(λ,1),λ∈R,a→与b→的夹角为θ.若θ为锐角,则λ的取值范围是____
A →③溴水 B →④
—How about your school?
—Oh,very good.You can't find ________ one in this city.