Mark Twain ........... the years after the Civil War the "Gilded Age"

• called

• calling

• he called

• his calls

Early............ toes instead of hooves on their feet

• horses

• had horses

• horses had

• horses having

............. grow close to the ground in the short Arctic summer.

• Above tundra plants

• Tundra plants

• Tundra plants are found

• For tundra plants

In 1867, ............. Alaska from the Russians for $7.2 million.

• purchased the United States

• to purchase the United States

• the United States purchase of

• the United States purchased

Between 1725 and 1750, New England witnessed an increase in the specialization of ................

• occupations

• occupies

• they occupied

• it occupied them

The large carotid artery .............. to the main parts of the brain.

• carrying blood

• blood is carried

• carries blood

• blood carries

................... radio as the first practical system of wireless telegraphy.

• Marconi's development

• The development by Marconi

• Developing Marconi

• Marconi developed

In 1975, the first successful space probe to ............... beginning to send information back to Earth.

• Venus

• Venus the

• Venus was

• Venus it was

The two biggest resort ............. Arkansas are Hot Springs and Eureka Springs.

• in

• towns in

• towns are

• towns are in

NASA's Lyndon B. Johnson Space Center .................. control center for the Mercury

• it was at the

• it was the

• was the

• the