吴女士与公司签订合同规定，公司每月支付给吴女士税后工资4500元，吴女士每月应缴纳的个人所得税由公司负担。如果不考虑保险和住房公积金因素，那么吴女士的税前工资为（）元。

A．4556.25 

B．4750 

C．4794.12 

D．4885

—Another cup of coffee? That’s your third since lunch.

—Yeah, well, I ____ all night preparing for my history exam. I can hardly keep my eyes open.

A．stayed up

B．have stayed up

C．have been staying up

D．will stay up