1、【题目】Blue－greenalgaegrowabundantlyinsaltmarshes.

选项：

A.primarily

B.slowly

C.onplants(cultivate)

D.ingreatnumbers

答案：

解析：

1、【题目】The megaphone(microphone) makes the voice sound louder because it points sound waves in one direction and keeps them from spreading out in all directions.

选项：

A.slithering

B.radiating

C.interfering

D.murmuring

答案：

B

解析：

暂无解析

1、【题目】The future survival of the bald eagle is still an important American ecological concern.

选项：

A.migration

B.population

C.existence

D.evolution

答案：

C

解析：

暂无解析

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】The Salk vaccine is a major factor in the fight to eradicate polio.

选项：

A.completelydestroy

B.carefullydisguise

C.sustain

D.contain

答案：

A

解析：

暂无解析