C. To help foreigners living in Beijing

　　D To improve the public understanding of error correction

10. What can we infer from the text?

　　A. The mistranslations are all direct translations.

　　B. the translation checks are done by experts

　　C. Fewer mistranslations of public signs remain in Beijing now.

　　D. The experts will search for mistranslations in the whole country.

11. What is the best title for the text?

　　A. Public Signs in Beijing

　　B. Mistranslations of Public Signs

　　C. A Correction Activity Starting in Beijing

　　D. Humorous Translations Removed in Beijing

　　Mobile-phone makers think they have a way to improve slowing sales: smartphones with big screens that fold up like books.

　　At least five of the world's leading sellers of phones, including Apple Inc., have tried to get patents for folding models, which would mark the biggest design change since the start of the smartphone era a decade ago. At least two companies- Samsung Electronics Co. and Huawei Technology Co. -have planned to sell smartphones with foldable screens; Huawei is planning to sell next year.

　　Smartphone companies see such a move as necessary to change a sales slowdown tied in part to a long cycle of phone replacement. These days, consumers see less of a need to upgrade for less obvious yearly improvements in software, screen quality and camera capability. In addition, creating screens that are larger but don't take up much space in a purse or pocket because urgent as service provides carry out next-generation 5G wireless networks.

Fisrt, though, smartphone makers must overcome some challenges, such as developing a phone able to fold in half that doesn't influence screen quality and working time. Other problems include supply-chain limitations for the required