He's not answering his cell phone. 他不接手机。

　　Will you please answer the phone? 你能帮我接个电话吗？

　　Please answer the door. 帮忙开下门。

　　Could you answer it for me? （电话铃响时）你能帮我接一下吗？（门铃响时）你能帮我开个门吗？

　　Did you answer the phone? 你接电话没？

　　I did, but they hung up as soon as I answered.  接了，不过我刚接起来，对方就挂电话了。