Living on theisland was ribterrible at first

a myth is something that is told for many years that u go looking for and cant find and a truth is something that u can find in real life and can be story's of for example:

mermaid's and unicorns: u can't find them at all so they can be a myth cause u hear story's about them once u go looking for them u won't find them.

dinassours(can't spell): u hear story's about them at school by ur friends and one day ur dad takes u to a museum and u find fossils of them so u realize they are real and not fake.

i would say the correct answer is not concrete.

answer; (d) i believe the best answer is ; ///people said that man could not fly, but in 1903, orville and wilbur wright made the first sustained powered flight in a heavier- than-air machine;

in other words

to put it differently

for one thing

as an illustration

in this case

for this reason

to put it another way

that is to say

with attention to

by all means

important to realize

another key point

first thing to remember

most compelling evidence

must be remembered

point often overlooked

to point out

on the positive side

on the negative side

with this in mind

notably

including

like

to be sure

namely

chiefly

truly

indeed

certainly

surely

markedly

such as

especially

explicitly

specifically

expressly

surprisingly

frequently

significantly

particularly

in fact

in general

in particular

in detail

for example

for instance

to demonstrate

to emphasize

to repeat

to clarify

to explain

to enumerate