or: 或者，否则，常用于否定句中 I don't like apples or bananas. Hurry up or you'll miss the bus.
and: 并且，Hurry up and you'll catch the bus.
这组词都有“加强”的意思，其区别是：
increase: v.指数量上的增加。
➤ The number of people has been increased.
人数增加了。
reinforce: v.增援，一般用于军队或警察的行动；(以添加材料等)加固。
➤ A police officer saw three thieves robbing a bank and radioed to reinforce him.
一位警察看到三个盗贼抢劫银行，用无线电话要求增援。
intensify: v.使变得更强烈、剧烈，加剧，相当于to become more intense or intensive。
➤ intensify colors
加深色彩intensify hatred加深仇恨
strengthen: v.加强，巩固，增强，相当于to become stronger。
➤ Exercising every day strengthens the heart.
每天锻炼可以提高心脏的功能。
➤ Competition, they believe, strengthens the national character rather than corrupt it.
人们认为竞争加强了民族性而不是破坏了它。
aggravate: v.加重(负担、罪行、病情等)，使之恶化。
➤ I hurt my foot, then aggravated it by trying to walk too soon.
我的脚受伤了，而过早的下地走路又加重了伤情。
enhance: 使…看起来更好；提高；美化
cement: （比喻）将…结合在一起；加强；巩固。如cement a friendship表示“加强友谊”
strengthen: 使…更强
magnify: 放大，扩大
strengthen: 加强，强化