－Have you made ______ apology to your mother?

－Yes. I regretted speaking to her in ______ rude manner.

A．an; a

B．an; /

C．the; a

D．/ ; the

气体以气泡形式侵入钻井液后，环空气侵钻井液的密度是随井深自下而上逐渐增大。