Hxen.com's tips：Every day persisted can learn English well!-->■Learn English Everyday■
phase - n. a part or step in a process
positively - adv. in a way that shows that you are hopeful and thinking about the good qualities of a situation
spike - n. a long, thin rod that ends in a point
efficacy - n. the power to produce a desired result or effect
determined - v. to learn or find out (something) by getting information
