第1个回答 2022-10-30
DDCA
One thing we do not know is how life began （57）in the sea about 3,000,000,000 years ago.
Scientists believe that life started when some tiny substances（物质） met other substances under exactly the right conditions.In the warm waters of an ancient seacoast,a little mass（一小团物质） was formed of water,chemicals,and salts（58）.This little mess had something which nothing on earth had had before:the power to recreate itself to fit surrounding conditions.In a word:life（59）.If life could be created then,why does it not happen today?Part of the answer is that the world now is very different from what it was when it was new.Long ago there was no other life to destroy very those very *** all bits of living matter（60）.Now it is probable that they would be destroyed(毁坏） by bacteria(细菌).
The oldest age for life was once thought to be 1,900,000,000 years.But in 1965,Dr.Melvin Calvin of the university of California,and a group of scientists,found tiny-substances that were 2,700,000,000 years old.In Africa other tiny substances were found that were 3,000,000,000 years old.It was formerly thought that no life had existed on earth during this period of time.
Today we have thousands of different kinds of plant and animal life.Yet all of them have one thing in mon:their origin（起源） in the sea.,2,英语阅读理解帮忙
One thing we do not know is how life began in the sea about 3,000,000,000 years ago.
Scientists believe that life started when some tiny substances（物质） met other substances under exactly the right conditions.In the warm waters of an ancient seacoast,a little mass（一小团物质） was formed of water,chemicals,and salts.This little mess had something which nothing on earth had had before:the power to recreate itself to fit surrounding conditions.In a word:life.
If life could be created then,why does it not happen today?Part of the answer is that the world now is very different from what it was when it was new.Long ago there was no other life to destroy very those very *** all bits of living matter.Now it is probable that they would be destroyed by bacteria(细菌).
The oldest age for life was once thought to be 1,900,000,000 years.But in 1965,Dr.Melvin Calvin of the university of California,and a group of scientists,found tiny-substances that were 2,700,000,000 years old.In Africa other tiny substances were found that were 3,000,000,000 years old.It was formerly thought that no life had existed on earth during this period of time.
Today we have thousands of different kinds of plant and animal life.Yet all of them have one thing in mon:their origin（起源） in the sea.
57.Now people know _____.
A.exactly how life came into being
B.nothing about life
C.for sure life started 3,000,000,000 years ago
D.not exactly how and life started
58.What were the most important thing in the forming of life?
A.Water,chemicals B.Water,chemicals,mass and the right conditions
C.Chemicals and salts D.Water,chemicals,salts and the right conditions
59.The mass in this passage was____
A.nothing unusual pared with any other substance
B.something that could grow huge
C.something that could produce masses of its own kind
D.something could grow very fast
60.Life could be recreate only when____
A.it had no natural enemies B.people know how to create
C.the water was warm D.there was bacteria