【多选题】下列磁性材料中,属于软磁性材料的有( )。
【单选题】叶是由茎尖生长锥周围何种结构发育而成的:
【单选题】3 yo female patient with bacterial meningitis Speciation: Streptococcus Pneumoniae She is Penicillin resistant and Cephalosporin sensitive Which antibiotic would be best for this patient?
【单选题】下列建筑材料中,不属于塑性材料的有( )。