Q:Read the following article and select the best answer. Article: Fruit powered digital clock Fruit's not only good to eat, but it can also power this Fruit digital Clock. This clock uses the scientific principles on which modern electrical storage batteries are based. The acid from the fruit helps transmit an electrical flow between two metal poles. The clock is priced at US $ 15. Connecting any fresh fruit or vegetable to the clock will make it work. The fruit is a clean, renewable source of electrical power. USB vacuum Do you know the dirtiest parts of your desk are probably your keyboard and mouse? Get a USB Mini Vacuum with retractable cable and suck away all that _ . The US- made product is priced at US $14. SIM card reader Making useful USB 2.0 multi-card readers even handier, this card can also read and write data to phone SIM cards. It comes with SIM editing software. Download your phonebook to your computer. If you lose your cell phone, you can store missing phone numbers in your new one. The US-made IMOMO SIM card + Multi Card Reader is priced at US $ 19 (152yuan). Beer in your ear The beer barrel -shaped Naf Naf Hyp MP3 is a musical box that's capable of playing radio, CDs and cassettes. It's got all the standard features of the typical clock-radio, but with the relaxing look of a big beer barrel. The Danish product is priced at about US $ 130 (1,040yuan) Question: What does "junk" mean in the second item? - dirt - desk - keyboard - mouse
A:
dirt