The speaker ________have criticized the paraprofessionals, knowing full well that they were seated in the audience.

A．should not to

B．must not

C．ought not to

D．may not

白磷和红磷燃烧的产物都是P₂O₅，但是相同条件下等量的白磷和红磷燃烧前者放出热量多。以下说法正确的是()

A．红磷比白磷稳定

B．白磷转化成红磷吸收热量

C．红磷转化成白磷为放热反应

D．等量的白磷和红磷相互转化时的能量变化值不相等