float

1. 我正忙着协调安排记者招待会。 I am in middle of arrange press conference

2. 我正忙着做正餐吃的馅饼，这时电话响了。the phone was rang when i was in middle of cooking pies for dinner
3. 父母突然返回时，他们正在开晚会。they ware meeting when their parents came back suddenly