Electromagnetic traps for atomic ions work well for experiments using a small number of ions --- they are completely impractical for large-scale systems.
in case
now that
whether
although
so long as
It was not obvious to scientists what the solution would be to the cosmic radiation astronauts are exposed to; ---- was it obvious that there would be any solution at all.
and
nor
but
either
so
He realized that the world could run out of key resources, ---- he was a harsh critic of the wastefulness of modern industrial society.
whether
but
so that
and so
so long as
The harder a material is, ---- ductile or workable it tends to be.
as much
the most
the less
more
so much
Certain reactions, ---- catalytic methanation, appear to stop before they are complete.
in case of
instead of
in place of
such as
with reference to
---- the car is equipped with a sophisticatedprotection system, you know you are fully protected.
Even if
Although
So
Until
Since
The trend of increasing carbon dioxide in the atmosphere is documented by the examination of air bubbles trapped in glacial ice ---- by direct measurements of the atmosphere.
because of
as well as
whereas
also
unless
Engineering structures must conform ---- to theirtype ---- to the laws of physics.
either / and
as / as
more / but
not only / but also
both / as
The book adheres ---- closely to a standard chemistry curriculum.
as
fairly
enough
such
seldom
Being a scientist does not prevent one from participating in other fields of human endeavour, --- being an artist does not prevent one from practising science.