英语翻译Well before classes start,students and teachers order La

英语翻译
Well before classes start,students and teachers order Lattes,Cappuccinos and Hot Chocolates.Then,during the first period,teachers call in orders on their room phones,and students make deliveries.
重点翻译：
1、during the first period这个短语是什么意思?
2、call in orders 怎么翻译?call in 是短语还是call in orders是短语?
最好把这个句子结构分析一下：teachers call in orders on their room phones,and students make deliveries.
teachers call in orders on their room phones,and students make deliveries.
这个句子的
主语：teachers
谓语：call 还是call in
宾语：
状语：