II. Complete the paragraph by filling-up the blanks with the correct word from the box below.
Stromatolites
Ocean
human beings
zircon crystal
4.6 billion years ago
Mesozoic Era
Cenozoic
3.0 billion years ago
Earth
Homo erectus
About (1)
the Earth was formed as the solar system came into existence with the
other planets rotating around the sun. (2)
is said to be geologically violent because of the
continuous bombardment by meteorites and volcanic eruptions. With this condition, minerals were forms from the elements
and compounds contained in the molten material. The oldest material found on earth is the (3)
that is estimated to be 4.3 billion years old. Life on earth is believed to begin 3.5 billion years ago with single-celled
prokaryotes, as discovered in sedimentary rock formations called (4)
As early as (5)
the first photosynthetic organism thrived the earth which is blue green algae called
cyanobacteria. It was 2.0 billion years ago when the first eukaryotes appeared and the influx of multicellular organisms
occurred 1.2 billion years ago. During the Paleozoic Era which lasted 542 to 251 MYA, the Cambrian and Ordovician Period
has been known as the age of onvertebrates when trilobites and cephalopods became dominant in the (6)
The (7)
is the age of reptiles that has a span of 251 to 65.5 MYA
divided into Triassic, Jurassic, and Cretaceous Period. (8)
is the era of recebt life and
based on paleontological evidence. (9)
have evolved 250 thousand years ago. (10)
are the only surviving species and one of the living evidences that life have existed on
earth.

(2) Earth is said to be geologically violent because of thecontinuous bombardment by meteorites and volcanic eruptions. With this condition, minerals were forms from the elements and compounds contained in the molten material.

The oldest material found on earth is the

(3) Zircon crystal that is estimated to be 4.3 billion years old. Life on earth is believed to begin 3.5 billion years ago with single-celled prokaryotes, as discovered in sedimentary rock formations called (4) Stromatolites.

As early as (5) 3.0 billion years ago the first photosynthetic organism thrived the earth which is blue green algae called cyanobacteria. It was 2.0 billion years ago when the first eukaryotes appeared and the influx of multicellular organisms occurred 1.2 billion years ago.

During the Paleozoic Era which lasted 542 to 251 MYA, the Cambrian and Ordovician Period

has been known as the age of onvertebrates when trilobites and cephalopods became dominant in the (6) Ocean.

The (7) Mesozoic era is the age of reptiles that has a span of 251 to 65.5 MYA divided into Triassic, Jurassic, and Cretaceous Period.

(8) Mesozoic era is the era of recebt life and

based on paleontological evidence.

(9) Homo erectus

have evolved 250 thousand years ago.

(10) Human being are the only surviving species and one of the living evidences that life have existed on earth.