题目内容
Thirty years ago, Lake Ponkapog was full of life. Many birds and animals lived beside the water, which was full of fish. Now there are few birds, animals and fish. The lake water is polluted. It is filled with strange plants.
How did this happen? First, we must think about how water gets into Lake Ponkapog. When it rains, water comes into the lake from all around. In the past, there were forests all round Lake Ponkapog, so the rainwater was clean. Now there are many homes around the lake. People often use chemicals in their gardens. They use other chemicals inside their houses for cleaning or killing insects. There are also many businesses. Businesses use chemicals in their machines or shops. When it rains, the rainwater picks up all the chemicals from homes and businesses and then carries them into the lake. They pollute the water and kill the animals.
Boats on the lake are also a problem. Lake Ponkapog is a popular place for motorboats. But oil and gas
（汽油）from boats often get into the lake. So more bad chemicals go into the water this way.People around the lake love their lake and want to save it. Will it be possible? A clean lake must have clean rainwater going into it. Clean rainwater is possible only if people are careful about chemicals at home and at work. They must also be more careful about gas and oil and other chemicals on the ground. And they mustn't use motorboats any more on the lake. All these may change people's lives. Only then can Lake Ponkapog be a beautiful clean lake again.
(1)In the past the water in Lake Ponkapog was made clean by ___________.
[ ]
|
A ．fish |
B ．rain |
|
C ．birds |
D ．forests |
(2)The third paragraph mainly tells us ____________.
[ ]
A
．people like to go boating on the lakeB
．some bad chemicalsC
．chemicals from motorboats also make the lake water dirtyD
．how oil gets into the lake water(3)To save the lake, people need to ___________.
[ ]
A
．be less careful about chemicalsB
．use less waterC
．grow fewer plants in the gardensD
．change their daily lives(4)
“Chemicals”in the story means“__________”.[ ]
|
A ．化学家 |
B ．污染品 |
|
C ．药品 |
D ．化学制品 |
(5)What makes the lake water dirty?
[ ]
|
A ．Chemicals. |
B ．Strange plants. |
|
C ．Rainwater. |
D ．Both A and B. |
解析：
|
(1) 由第二段的In the past, there were forests all round Lake Ponkapog, so the rainwater was clean.可知。(2) 由第三段的But oil and gas from boats often get into the lake. So more bad chemicals go into the water this way.可知答案为C。(3) 文章最后两句点题。(4) 由文意及常识可知。(5) 由文章知，是人们使用的各种化学制品最终污染了湖水。 |
小博士：仔细观察下面的基数词和对应的序数词的区别和变化，你会发现这种变化是有规律的，你能归纳出来吗？请根据规律填出所缺的基数词和序数词，并特别注意黑体字的词。
one | first | eleven | eleventh | twenty-one | twenty-first |
two | second | twelve | twelfth | twenty-two | twenty-second |
three | third | thirteen | thirteenth | twenty-three | twenty-third |
four | fourth | fourteen | fourteenth | twenty-four | ______ |
five | fifth | fifteen | ______ | twenty-five | twenty-fifth |
six | sixth | sixteen | sixteenth | twenty-six | twenty-sixth |
seven | ______ | seventeen | seventeenth | twenty-seven | twenty-seventh |
eight | eighth | eighteen | eighteenth | twenty-eight | twenty-eighth |
nine | ninth | nineteen | nineteenth | twenty-nine | twenty-ninth |
ten | tenth | twenty | twentieth | thirty | thirtieth |
thirty-one | thirty-first fortieth ninetieth | hundred | hundredth | ||
forty | thousand | thousandth | |||
ninety | million | millionth | |||
我找到规律了！请看：
1 英语序数词1～19，除first，second，third等特殊形式外，其余的一般是在相应的基数词后加-th构成。
2 有几个序数词加-th时拼法不规则，要注意。如fifth，________ ________ ________。
3 十位整数的序数词的构成方法是先将其基数词的词尾“ty”中的“y”改为“i”，再加“-eth”。如________。
4 基数词“几十几”变成序数词时，只需将个位数变成序数词，十位数不变。如________。