Variant-1 Choose the answer which correctly completes the sentence

each question below, according to the text (19-22).
Mark and Gerald are identical twins. Mirror
images of each other, they also share many
similarities in lifestyle. Mark hasn’t ever been
married, and Gerald hasn’t either. Mark is a
firefighter, and so is Gerald. Mark likes hunting,
fishing, going to the beach, eating Chinese food,
and watching John Wayne movies. Gerald does
too.
These similarities might not be unusual in
identical twins, except for one fact: Mark and
Gerald were separated when they were five days
old and grew up in different states with different
families. Neither Mark nor Gerald knew that he
had a twin. The two men found each other
accidentally when they were thirty-one, and they
discovered their almost identical lifestyles at that
time.
Average people are fascinated by twins like Mark
and Gerald. So are serious researchers. Identical
twins share the same genes. Therefore, they offer
researchers the chance to study the effect of
genetic inheritance on disease, length of life, and
personality.
19. Mark and Gerald share many similarities in
lifestyle because . . .
A)they know each other very well.
B)they are identical twins.
C)they live in the same neighbourhood.
D)they are best friends.
20. How did they find each other?
A)They were in the same university.
B)They asked the police to help them find each
other.
C)They met by chance.
D)They participated in the same training program.
21. Twins like Mark and Gerald fascinate both
average people and serious researchers, because . . .
A) they made an outstanding scientific discovery.
B) they won a Nobel Peace prize.
C) they went to the Moon.
D) they have almost identical lifestyle despite living
separately.
22. They offer researchers the chance to study . . .
A) the wildlife of South America.
B) the history of the Middle East.
C) the effect of genetic inheritance.
D) the behaviour of children.