Key Points of 1a
1.Could I order a meal by phone?我可以通过电话订餐吗?(1)order定购，点（菜)
E.g:他点了一盘鱼。
He ordered a plate of fish.
(2)by+n./v.-ing（表示方法、手段）用;由
E.g:她靠卖花赚钱。She makes money by selling flowers.2.That's all.就这些了。
3.We'll send the food to you in thirty minutes.三十分钟后，我们会把食物送到。
(1) send...to..把..…...送到…....
E.g:他昨天给我捎来一个消息。
He sent the message to me yesterday.
(2)in+一段时间，意为“...….之后”，用于一般将来时，用How soon提问。E.g:李先生什么时候回来?他三小时后回来。

You may retell the dialog like this:
Mr. Zhao knows that the students in Beijing InternationalSchool are holding a food festival.But he is busy these days,so he can't come to the food festival.He ordered a meal byphone. He ordered fried rice,roast chicken and a bottle oflemon tea. And he told Kangkang that his office is at No.62on Beisihuan Road. Kangkang's classmate will send the foodin thirty minutes.