O-Net 2020

(Items71-80)

                           Getting the Drift
Most snow falls from extensive banks of stable nimbus clouds. The
genesis of a snowflake requires fairly slow and continuous crystallization
with little turbulence. If the wind continues to carry clouds toward high
ground, or if a warm air mass slides smoothly over a cold one, snow can
5 persist for as long, and over as large a continuous area, as ordinary
rainfall.
Hailstones are formed in conditions of violent convection inside tall,
isolated, unstable cumulonimbus clouds where there is very strong internal
circulation, Mosthailstones have a layered structure, showing that they
10 have been cycled several times between freezing and melting levels.
Eventually the cloud grows to the point where its shadow prevents the sun
from heating the ground which normally supplies the rising thermals
necessary to keep the stones airborne, and so they fall in a brief, localized
burst.
15 Deep layers of hail do occur but, as the largest cumulonimbus clouds
are formed on clear sunny days over hot ground, and as the same cloud
may also precipitate warm rain, hailstones tend to melt quickly. As hail is
macroscopically denser than fresh snow, the same mass of water will
produce a much deeper layer of snow over a given area

The first paragraph gives information about _____.
1. what nimbus clouds are
2. when crystallization begins
3. what snowflakes lookl ike
4. how snow forms
5. how many days snow lasts

Answer: 4. how snow forms

Snow is created when
1. large masses of stable clouds slowly become crystallized
2. nimbus clouds become snowflakes and move over ground
3. strong wind carries unstable clouds toward high ground
4. frozen cloud spersist over a large area of highland
5. clouds stop forming a great amount of snowflakes

Answer: 1. large masses of stable clouds slowly become crystallized

The word "genesis" (line 2) means _____.
1. origin
2. life
3. falling
4. melting
5. movement

Answer: 1. origin

The word "one" (line 4) refers to _____.
1. wind
2. ground
3. air mass
4. snow
5. cloud

Answer: 3. air mass

The word "localized" (line13) means _____.
1. occurring anywhere
2. happening within one small area
3. existing in a remote place
4. spreading over the ground
5. appearing everywhere

Answer: 2. happening within one small area

Snow is compared to rainfall in that both snow and rainfall
1. exist when a warm and cold air mass meet
2. can last long and cover alarge area
3. originate from a large mass of cumulonimbus clouds
4. pass the process of turbulence before falling
5. require slow and continuous crystallization

Answer: 2. can last long and cover alarge area

Hailstones are formed when _____.
1. there are very sudden changes around cumulonimbus clouds
2. there is strong circulation within cumulonimbus clouds
3. strong circulation bursts out from inside cumulonimbus clouds
4. cumulonimbus clouds are isolated and stable
5. the clouds undergo slow changes

Answer: 2. there is strong circulation within cumulonimbus clouds

Hailstones do not last long because they _____.
1. have layered structure resulting from cycling repeatedly
2. prevent the sun from shining over the ground
3. are formed on clear sunny days over hot ground with warm
    rain
4. are too big and too heavy to spread over the ground
5. fall suddenly due to their densit

Answer: 3. are formed on clear sunny days over hot ground with warm
    rain

All the statements are true EXCEPT: _____.
1. a snowflake is formed through slow, continuous and steady
    crystallization
2. the same mass of water produces a much deeper layer of snow
    than hail
3. hail is denser than snow but can form a much deeper layer of
    fallen hail
4. heat rising from the ground prevents hailstones from falling
5. hailstones can melt quickly on clear sunny days with warm rain

Answer: 2. the same mass of water produces a much deeper layer of snow
    than hail

It can be inferred from the passage that _____.
1. snowflakes become snowstorms with little turbulence
2. snowstorms and hailstorms are produced from the same kind of
    clouds
3. snowstorms last longer and produce ad eeper layer of hailstones than
    hailstorms do
4. the conditions within cloud can result in different kinds of natural
    phenomena
5. snow and hailstones are produced in the same way

Answer: 4. the conditions within cloud can result in different kinds of natural
    phenomena