Mark the letter A, B, C, or D on your answer sheer to indicate the underlined part that needs correction in each of the following questions.

What we know about certain diseases are still not sufficient to prevent them from spreading easily among the population.

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions.

I don't suppose there is anyone there, __________?

Read the following passage and mark the letter A, B, C or D on your answer sheet to choose the word or phrase that best fits each other numbered blanks. 

Library is a collection of books and other informational materials made available to people for reading, study, or reference. The word library comes from liber, the Latin word for "book". (3) ________, library collections have almost always contained a variety of materials. Contemporary libraries maintain collections that include not only printed materials such as manuscripts, books, newspapers, and magazines, but also audio-visual and online databases. In addition to maintaining collections within library buildings, modern libraries often feature telecommunications links that provide users with access to information at remote sites. The central mission of a library is to collect, organize, preserve, and provide access to knowledge and information. In fulfilling this mission, libraries preserve a valuable record of culture that can be passed down to (4) ________ generations. Libraries are an essential link in this communication between the past, present, and future. Whether the cultural record is contained books or in electronic formats, libraries ensure (5) ______ the record is preserved and made available for later use. People use library resources to gain information about personal interests or to obtain recreational materials such as films and novels. Students use libraries to supplement and enhance their classroom experiences, to learn (6) _______ in locating sources of information, and to develop good reading and study habits. Public officials use libraries to research legislation and public policy issues. One of the most valued of all cultural institutions, the library (7) ________ information and services that are essential to learning and progress.