TOEFL Structure and Written Expression 2 (Longman PBT)

In the early 1900s, Eastman __ inexpensive Brownie box cameras.

__ the discovery of the fossilized remnants of tides in one-billion-year-old rocks.

The Brooklyn Bridge __ took thirteen years to complete.

Genes control all of the physical __ we inherit.

Indigo can be extracted from a plant, and then __ to dye cloth blue.

__ in the United States spends 900 hours per year in class and 1,170 hours in front of the television.

Researchers have begun studying what __ is on human circadian rhythms.

If calcium oxide remains exposed to air, __ to calcium carbonate.

Some early batteries used concentrated nitric acid, __ gave off poisonous fumes.

The sound produced by an object __ in a periodic way involves more than the simple sine wave.