VOA慢速英语:High Demand from Investors for Special US Visas

via – preposition by means of (a person, machine, etc.); by using (something or someone)

riddle – v. to fill (something) with something that is bad or unpleasant -- usually used as “riddled with”

incentive – n. something that encourages a person to do something or to work harder

plague – v. to cause constant or repeated trouble, illness, etc., for (someone or something)

background – n. the experiences, knowledge, education, etc., in a person’s past

characterize – v. to describe the character or special qualities of (someone or something)

confer – v. to give (something, such as a degree, award, title, right, etc.) to someone or something -- usually + on or upon