Structure and Written Expression

The ponderosa pine is ... of the most of the timber used by forest product firms in the Black Hills of South Dakota.

• the source

• as source

• the source which

• because the source

Computers that once took up entire rooms are now ... to put on desktops and into wristwatches.

• small enough

• smaller than

• so small

• as small as

According to some educators, the goal of teaching is to help students learn what ... to know to live a well-adjusted and successful life.

• do they need

• they need

• they are needed

• as they may need

The sapphire's transparency to ultraviolet and infrared radiation makes ... in optical instruments.

• is it of use

• it uses

• it a useful

• it useful

... initial recognition while still quite young.

• Most famous scientists achieve

• That most famous scientists achieved

• Most famous scientists who achieved

• For most famous scientists to achieve

Margaret Mead studied many different cultures and she was one of the first anthropologists to photograph hers subject.

• studied

• different

• of the first

• hers

Talc, a soft mineral with a variety of uses, sold is in slabs or in powdered form.

• a

• variety

• sold is

• form

During the 1870's iron workers in Alabama proved they could produce iron by burning iron ore with coke, instead than with charcoal.

• During

• could

• burning

• instead

Geologists at the Hawaiian Volcano Observatory rely on a number of instruments to studying the volcanoes in Hawaii.

• Geologists

• rely

• a number

• to studying

Underlying aerodynamics and all other branches of theoretical mechanics are the laws of motion who were developed in the seventeenth century.

• all

• branches

• are

• who