how to distinguish the fact from opinion

how to distinguish the fact from opinion
Decide if the following
sentences are fact,opinion,or a blend of both.Write F for fact,O for opinion,and B if the
sentence has both some fact and opinion.
11.Because
of a newly formed and largely incompetent national weather service,the city of
Galveston,Texas was practically destroyed in a horrifying hurricane that left
thousands dead.F
12.
In 1852,the President of the United States,Franklin Pierce,was greedy to expand
U.S.influence,and he formally offered to buy the island of Cuba.F
13.
Helping students evaluate websites is a challenge for parents,teachers,and
librarians.O
14.
On December 7,1941,the Japanese attacked Pearl Harbor.After the attack,America officially entered
into World War II.F
15.Rats are dirty animals because they carry
diseases and live in sewers[ˈsu:ə].污水管
O
16.Area 51 in Nevada is the site of a U.S.Government UFO cover-up.f
17.Dr.Martin Luther King believed that people
should not use violence to fight injustice,should not be judged by the color
of their skin,and that all people were created equal.O
18.Dr.King was a great public speaker.His most famous speech is entitled,“I Have aDream.” o
19.Because of new and
modern technology,it has become easier than ever to communicate with people on
the other side of the world.O
20.After Mrs.Brown had 14
hours of cosmetickɔzˈmetik 化妆的 surgery[英] [ˈsə:dʒəri],she was in a great deal of pain.
F
答案不一定是对的 求大家检查并给正确答案