Noun and Adjective Clause

Early in the eighteenth century, Halley accurately predicted when _____ of 1682 would return.

• had the comet

• the comet

• was the comet

• the comet was

The National Institute of Dental Research estimates _____ in fluoridated areas have about 25 percent less tooth decay than children elsewhere.

• that for school children

• for school children

• school children's

• that school children

Minute Man National Historical Park is a monument to where _____

• the Revolutionary War to begin

• the Revolutionary War began

• the beginning of the Revolutionary War

• in the beginning of the Revolutionary War

Today, the true story of _____ at Little Bighorn remains a mystery.

• happened

• it happened

• what happened

• what happening

No single factors explains why _____ vary so greatly among individuals.

• the aging effects

• aging effects

• the effects of aging

• aging has an effect

For more than a decade, ____ that certain species are becoming scarce.

• bird-watchers have warned

• a warning for bird-watchers

• the warnings of bird-watchers

• warn the bird-watchers

The process of photosynthesis explains how _____ able to use the energy in sunlight to manufacture foods from the simple chemicals in air and water.

• planting greens

• with green plants are

• green plants

• green plants are

Lack of clarity about _____ the party in the coming year will be removed at the party's convention.

• lead

• they will lead

• who will lead

• will lead

Tests on the colors of cars were conducted at the University of California to determine _____ the safest colors for cars.

• which were

• if

• how were

• which

We do not _____ the bow drill was first developed for woodworking or fire making.

• know whether it

• know whether

• sure whether

• whether it