We had a class with a substitute teacher because our regular teacher was unavailable today.
今天是代课老师给我们上的课，因为我们老师缺席了。
substitute /ˈsʌb.stɪ.tʃuːt/
v. substitute for something to use something or someone instead of another thing or person
代替
Eg. You can substitute oil for butter in this recipe.
这个食谱里你可以用油代替黄油。
n. a thing or person that is used instead of another thing or person
代替品
There is no substitute for something
没有比某事更好的
Eg1. You can learn English by self-studying, but there’s no substitute for visiting an English-speaking country and talking to English speakers.
你可以自学英语，但是都不如亲自来国外和歪果仁对话。
Eg2. a substitute teacher 代课老师
Joe said that Candy was so dedicated in working on those words.
Joe说Candy付出很多精力在这些单词上。（这里的dedicated是形容词）
dedicate /ˈdedɪkeɪt/
v. to give a lot of your time and effort to a particular activity or purpose because you think it is important
dedicate yourself/something to (doing) something
Eg. Candy dedicates herself to writing the scripts of her final film.
Candy全身心投入在写她的期末电影的剧本上。
dedicated /ˈdedɪkeɪtɪd/
adj. working hard at something because it is very important to you
投入的，专注的（因为重要）
Eg. Candy is dedicated to her film.
Candy投入在她的电影上。
You can apply templates that are built-in to PowerPoint, created by you and then saved to your computer, or downloaded from third-party Web sites.
你可以用PowerPoint上自带的模板，或者你自己创建一个模板存在电脑里，也可以从网站上下载模板。
template /ˈtempleɪt/
n. a thing that is used as a model for producing other similar examples.
模板
Eg. new from template新建模板
这些都是template