1 99 5年英语试题S e c t io n Ⅰ Us e o f En g l i shS leep i s d i v i ded i nto p eriods o f s o-ca ll ed REM s leep, characterized b y rapid ey e movement s and dreami n g, and long e r per iod s of no n-R E M s leep. 1 kin d o f sleep i s at all wel l-u nder st ood, but R E M sle e p is 2 to ser v e some res torati ve f u nction of the brain. T he pu rpos e o f non-REM slee p is ev e n mor e 3 . The ne w expe rim ents, suc h a s the s e 4 f o r th e fi rs t tim e at a rece n t meet i ng of the Society f o r Sleep Re s e ar ch in M i nne apoli s, su g g e st f as ci nati n g expla n a tion s 5 of n o n-R EM sl ee p.For exa m ple, it h as l ong be e n kno w n th at t o t a l sleep 6 is 1 0 0 p ercent f atal t o rats, y et, 7 examina t ions o f the dead b odies, th e animals lo ok c omplete l y n orm a l. A researcher h as no w 8 th e myste r y of why t he a n imals die. The ra ts 9 bacterial i n fect ions of t h e bloo d, 10 t h eir i m mu ne sy st ems—the self-pr o te ct ing m e c ha n is rn ag ai nst di s e as e—ha d crashed.1. [A] Ei t herﻩ [B] Nei t herﻩ[C] Eac hﻩ [D] Any2. [A] i ntendedﻩ [B] req u ire d[C] ass u medﻩ [D] i nf erre d3. [A] subt l e ﻩﻩ [B] o bv iousﻩ[C] m y steri o usﻩ [D] do ubtful4. [A] maintain e d [B] describe d[C] se ttle dﻩﻩ [D] a f forde d5. [A] in the l ightﻩﻩ [B] by v ir t u eﻩﻩ[C] w i th the exception[ D] f...