21．Who may be a huge fitness enthusiast?

　　A．Melissa Ho.　　　　　　 B．Sylvia Colella.

　　C．Martin Dahinden. D．Kwame Alexander.

　　解析：选B　细节理解题。根据Sylvia Colella部分中的"One thing that keeps me motivated is great­looking workout or athletic wear"可知选B项。

　　22．How much should you pay at least if you buy a Swiss Army Knife and Hankins's book?

　　A．＄35.90. B．＄53.03.

　　C．＄54.97. D．＄90.87.

　　解析：选B　细节理解题。根据Martin Dahinden部分中的"Victorinox Swiss Army Spartan Ⅱ Pocket Knife, ＄ 17.13"以及Melissa Ho部分中的"Robert Irwin: All the Rules Will Change by Evelyn C. Hankins, ＄ 35.90"可知选B项。

　　23．Which of the following is the most suitable for kids?

　　A．We Shall Overcome.

　　B．Koral Lustrous Legging.

　　C．Robert Irwin: All the Rules Will Change.

　　D．Victorinox Swiss Army EvoWood 17 Swiss Army Knife.

　　解析：选A　细节理解题。根据Kwame Alexander部分中的"A children's book gift basket with some of my favorites ...We Shall Overcome，"可知选A项。

　　B

　　Robotic surgery is one thing, but sending a robot inside the body to carry out an operation is quite another, which has long been a goal of some researchers to produce tiny robotic devices being capable of traveling through the body to deliver drugs or to make repairs without the need for a single cut, the possibility of which has just got a bit closer.

　　However, unlike the plot of one film－which featured a microscopic crew and submarine traveling through a scientist's bloodstream - this device could not be inserted into blood vessels (管) because it is too big. While other types of miniature swallowable robots have been developed in the past, their role has mostly been limited to capturing images inside the body. In a presentation this week to the International Conference, Daniela Rus and Shuhei Miyashita of the Massachusetts Institute of Technology described a robot they have developed that can be swallowed and used to collect dangerous objects accidentally taken in.

To test their latest version, Dr Rus and Dr Miyashita designed a robot as a battery