1、【题目】Although the Carbon 14 method of dating old objects is not foolproof , it is the best method available at present

选项：

A.whollyoperational

B.entirelyserviceable

C.fullyreliable

D.completelysafe

答案：

C

解析：

暂无解析

1、【题目】AlthoughtheCarbon14methodofdatingoldobjectsisnotfoolproof,itisthebestmethodavailableatpresent

选项：

A.whollyoperational

B.entirelyserviceable

C.fullyreliable

D.completelysafe

答案：

解析：

1、【题目】Themegaphone(microphone)makesthevoicesoundlouderbecauseitpointssoundwavesinonedirectionandkeepsthemfromspreadingoutinalldirections.

选项：

A.slithering

B.radiating

C.interfering

D.murmuring

答案：

解析：

1、【题目】The controls of most modern airplanes can be operated either manually or automatically.

选项：

A.bythebook

B.byamap

C.bylogic

D.byhand

答案：

D

解析：

暂无解析

1、【题目】The Native American interpreter Sacajawea was a valuable member of the Lewis and dark expedition in 1805.

选项：

A.veryfriendly

B.veryuseful

C.verythoughtful.

D.verywealthy

答案：

B

解析：

暂无解析

1、【题目】Blue－green algae grow abundantly in salt marshes.

选项：

A.primarily

B.slowly

C.onplants(cultivate)

D.ingreatnumbers

答案：

D

解析：

暂无解析

1、【题目】Bats fly, rather than glide, and thus are the only mammals capable of true flight.

选项：

A.straight

B.safe

C.real

D.rapid

答案：

C

解析：

暂无解析

1、【题目】ThefirstimportantexpositionintheUnitedStateswasheldinPhiladelphiain1876.

选项：

A.exhibition

B.concert

C.excursion

D.contest

答案：

解析：

1、【题目】Double Eagle in the first transatlantic balloon, was greeted by avid crowds in France.

选项：

A.eager

B.surging

C.appreciative

D.vigorous

答案：

A

解析：

暂无解析

1、【题目】One of the greatest breakthroughs for professional women came in 1973 when the field of banking opened up for them.

选项：

A.mostseriousdisappointments

B.mostsignificantadvances

C.mostabruptdeclines

D.mostcrucialsituations

答案：

B

解析：

暂无解析