—How old is Steve?

—He is ____________ and he has an ___________ sister.

A．13-year-old; 10 years old

B．13 years old; 11-year-old

C．13 years old; 10-years-old

D．13-years-old; 11-years-old

牙科设备消毒时，综合治疗台的表面可考虑用

A．一次性纸巾覆盖

B．布巾覆盖

C．塑料布覆盖

D．消毒液擦拭

E．毛巾覆盖