在一个处于平衡状态的密闭生态系统内，要使物质循环能长期进行下去，必须提供（）

A.氧气

B.水

C.足够的有机物

D.太阳能

Section Ⅰ Use of English Directions: Read the following text. Choose the best word(s) for each numbered blank and mark A, B, C or D on ANSWER SHEET 1. Illiteracy may be considered more as an abstract concept than a condition. When a famous English writer used the (1) over two hundred years ago, he was actually (2) to people who could (3) read Greek or Latin. (4) ,it seems unlikely that university examiners had this sort of (5) in mind when they reported on "creeping illiteracy" in a report on their students’ final examination in 1988. (6) the years, university lecturers have been (7) of an increasing tendency towards grammatical sloppiness, poor spelling and general imprecision (8) their students’ ways of writing; and sloppy writing is all (9) often a reflection of sloppy thinking. Their (10) was that they had (11) to do teaching their own subject (12) teaching their undergraduates to write. Some lecturers believe that they have a (n) (13) to stress the importance of maintaining standards of dear thinking (14) the written word in a world dominated by (15) communications and images. They (16) on the connection between clear thinking and a form of writing that is not only clear, but also sensitive to (17) of meaning. The same lecturers argue that undergraduates appear to be the victims of a "softening process" that begins (18) the teaching of English in schools, but this point of view has, not (19) , mused a great deal of (20) .

Read the following text. Choose the best word (s) for each numbered blank and mark A, B, C or D on ANSWER SHEET 1.2（）

A．complaint

B．request

C．appeal

D．assertion