—Do you know where I can get someone ______ my skirt?

—You can have your skirt ______ at Main Street Cleaners.

A．to shorten; shorten

B．to shorten; shortened

C．shortened; shortened

D．shortened; to shorten

木材由于纤维排列的不正常而出现的倾斜纹理称为斜纹。斜纹会引起（），并能降低木材的强度。