朗读下面短文，体会、领悟加黑连词的用法及引导的状语从句的类型。
My mother was cooking in the kitchen while①I was doing my school assignments. As soon as②I finished my homework, I went to get some water to drink. Then the doorbell rang. However, my sister unlocked the door before③I could open it. We were surprised the moment④we saw her because⑤her clothes and face were terribly dirty.She looked much poorer than⑥we expected. Since⑦we didn't know what had happened to her, we stood there and waited for my sister's story.We wouldn't leave unless⑧my sister told us all about it.After⑨my sister got changed, she told us that she fell into a ditch when⑩she walked on a path on her way to my uncle's home in the countryside. She couldn't get out of the ditch.Although?she cried for help, no one could hear her. She tried to climb out of it, but, however?hard she tried, she failed to escape from it.As?time went by, she got worried. After several vain attempts she had to stand where?she was and waited until?a boy student passed by and gave her a hand. The boy reached her a long rope and told her to climb with the rope.She did as?the boy told, so? she came out.My sister also warned us to be careful when walking?on a path even though/if? we are in a great hurry.That's true. We should mind our step so that?we can ensure our safety.
