1、Doctor Liu is on call at all times.不论什么时候刘医生随叫随到。

2、I'll be on call the night of the party.在聚会的晚上我将随时听凭召唤。

3、In theory I'm on call day and night.从理论上说，我现在昼夜待命。

4、Would you be required to be on call or work overtime?你是否要做到随叫随到，是否需要加班