A.the sipmlest solution

　　B.the solution of simplest

　　C.the solution that simplification

　　D.which solution simplest

　　2)The poet MM spent several years ___ school in CP.

　　A.had taught

　　B.teaching

　　C.her teaching

　　D. and to teach

　　3)When the US C authorized a postal service in 1789,  ___ 75 local offices.

　　A.the nation having

　　B.has the nation

　　C.the nation had

　　D.for the nation to have

　　4)___ places on the Earth where plant and animal life has not been affected by the activities of humans.

　　A.The few

　　B.Being few

　　C.There are fewb

　　D.Few

　　5)___ nerve pathways conect the eye directly to the pineal gland, that gland is extremely sensitive to light.

　　A.Because

　　B.That

　　C.How

　　D.By

　　6)Chrom……s vary in size and shape and usually ___ in pairs.

　　A.occurring

　　B.to occur

　　C.occur

　　D.as occur

　　7)SL became the first VS woman ___ abroad the RM space station. A.who working

　　B.has worked

　　C.was working

　　D.to work