Now that she is out of a job, Lucy ______going back to school, but she hasn’t decided yet.

A．had considered

B．has been considering

C．considered

D．is going to consider

下列厨房里发生的现象，一定不涉及化学变化的是（　　）

A．煤气燃烧

B．铁锅生锈

C．水的沸腾

D．蔬菜腐烂