A woman with two children ________ along the street at the moment.
A:is walking
B:are walking
C:walk
D:walks
化学键
P﹣P
P﹣O
O=O
P=O
键能/kJ•mol﹣1
197
360
499
X
已知白磷的燃烧热为2378.0kJ/mol,白磷完全燃烧的产物结构如图所示,则上表中X=kJ•mol﹣1.( )