Question

TASK 4: Here are some
sentences from the
passage. Fill in the gaps
with prepositions from the
box:
Ву
for
of
in
to
The colour of the light (corresponding to the
energy of the photons) is determined by the
energy required electrons........
...... cross
the band gap of the semiconductor. White light
is obtained
............ Using multiple semi
conductors or a layer............... light-emitting
phosphor on the semiconductor device.
Appearing as practical electronic components in
1962, the earliest LEDs emitted low-intensity​

Answer 1

Answer:

soory i do not know

Explanation:

soory i do not know

Answer 2

Answer:

To,

By ,

Of

these are the answer of your questions