情景十九：现在不方便接电话
　　1. She has a visitor at the moment. 她现在有客人。
　　2. He is in a meeting now. 他正在开会。
　　3. I'm sorry, but he is unable to come to the phone now.很抱歉，他现在无法接电话。
　　4. I'm sorry, but I was just on my way out. Can I get back to you later? 很抱歉，我正好要出门。可不可以稍后再打给你。