Which statements about geologic time are true? Check all that apply.
U Scientists developed the geologic time scale as they studied rock layers and index fossils
The fossil record helps scientists describe life only in the seas and other bodies of water.
Precambrian time is the most recent time in Earth's history.
Precambrian time makes up 88 percent of Earth's history.
The first birds appeared during the Jurassic period.
O The basic units of the geologic time scale are periods, eras, and centuries.
Humans appeared during the Cenozoic era.
Intro

The fossil record helps scientists describe life only in the seas and other bodies of water. Precambrian time makes up 88 percent of Earth's history. The first birds appeared during the Jurassic period. Humans appeared during the Cenozoic era.

Explanation:

Let's examine the given statements:

Scientists developed the geologic time scale as they studied rock layers and index fossils .

Yes It is the initial method developed in 19th century. Together with this, radiometric dating methods are used in geo- chronology to establish the geologic time scale.

The fossil record helps scientists describe life only in the seas and other bodies of water.

NoThis method is not restricted in life only in the seas and water bodies. There are many examples of fossils found in different types of rocks whilst the primary source being sedimentary rocks.

Precambrian time is the most recent time in Earth's history.

NoPrecambrian is the whole period of earth's history before the formation of the oldest rocks with recognizable fossils in them. This is the earliest time in Earth's history.

Precambrian time makes up 88 percent of Earth's history.

YesThe Precambrian Era comprises all of geologic time prior to 600 million years ago.

The first birds appeared during the Jurassic period.

YesBirds first appeared in the Jurassic, having evolved from a branch of theropod dinosaurs.

The basic units of the geologic time scale are periods, eras, and centuries.

NoCorrect Eons ⇒ eras ⇒ periods ⇒ epochs ⇒ ages

Humans appeared during the Cenozoic era.

YesThe Cenozoic Era (meaning “new life”) is the current and most recent geological era, and covering the period from 66 million years ago to the present.

Exposed great deposits of coal and iron ore