VOA慢速英语:美国宇航局数十年来首次向私人公司寻求宇航员登月器

capsule – n. a small container

contract – n. a business agreement

elevator — n. a machine used for carrying people and things to different levels in a building

ladder – n. a structure used for climbing up or down something

efficiency – n. the ability to do something or produce something without wasting materials, time, or energy; the quality of being efficient

cargo – n. something that is carried from one place to another by boat or airplane

participate – v. to be involved with others in doing something; to take part in an activity or event with others

excite – v. to cause strong feelings or interest