A brilliant idea occurred to him, ___ to his research in the lab.

A．while devoting

B．while devoting himself

C．while he was devoted

D．while devoted

在漆膜上产生针状小孔或橡皮革的毛孔那样的孔称为（）级。

A、凹洼

B、拉丝

C、针孔

D、气泡