下列各项中，不会影响流动比率的业务是（）。

A．用现金购买短期债券

B．现金购买固定资产

C．用存货进行对外长期投资

D．从银行取得长期借款

He went out without a coat, _______it was very cold.         [ ]

A. but

B. though

C. since

D. because