When I went into her room, she was ________ in her work.

A．absorbed

B．controlled

C．exposed

D．developed

反应A(g)+3B(g)2C(g)+2D(g)，在不同情况下测得反应速率，其中反应速率最快的是（    ） 

A．υ(C)="0.4" mol / (L·s)           B．υ(B)="0.45" mol / (L·s)

C．υ(A)="0.15" mol / (L·s)          D．υ(D)="0.35" mol / (L·s)