II、Cloze:
The idea of traveling forward into the future or
back into the past has always interested science fiction
writers. Is there really _20_ a thing as time travel? Or
is it in fact _21_ sci-fi fantasy? The concept of time
travel seems to sound _22_ and impossible. However,
some scientist _23_ a way of proving the possibility of
time travels, using Einstein’s theories to underpin their
arguments. Part of the reason why the idea of time
travel is hard to grasp is that its laws of physics differ
_24_ the classics of physics we normally use to explain
the world. Einstein’s theories predict that _25_ a
spaceship moves, the slower time ticks inside of it.
Einstein’s special theory of relativity is based on the
_26_ speed of light and the fact that speed is not
absolute; when a helicopter lifts off, it can be thought
that it’s the helicopter _27_ stands still and the earth
that moves. This theory describes the relation between
time, space and motion in time travel. 【題組】27. (A) when
(B) where
(C) what
(D) that
I