下列各项中属于套汇的行为有( )

A．某境内酒吧以外币计价并以外币结算

B．某旅行社以人民币为外宾支付在境内的费用，由对方付给外汇

C．某企业私自改变外汇用途

D．黑市私自买卖外汇

The nurse is caring for a bedridden, elderly adult. To prevent pressure ulcers, which intervention should the nurse include in the care plan ？（）

A．Turn and reposition the client a minimum of every 8 hours.

B．Vigorously massage lotion into bony prominences.

C．Post a turning schedule at the client's bedside.

D．Slide the client, rather than lift, when turning.