下列关于当事人约定违约金的正确表述有( )。

A．合同中必须约定违约金

B．约定的违约金低于实际损失，当事人可以请求法院或仲裁机构裁定予以增加

C．约定的违约金过分高于实际损失，当事人可按违约金执行

D．合同中未约定违约金，当事人一方有权要求违约方依法支付违约金

E．当事人就迟延履行约定违约金的，违约方支付违约金后，还应履行债务

I'm tired out. I ______ all afternoon and I don't seem to have finished anything.

A. shopped


B. have shopped
C. had shopped


D. have been shopping