To
keep
our city clean, we can take
the bus or the metro to school. We can't throw
the rubbish on the ground and we can put
it in the bin. We can plant
more trees.答案：【解析】：本题主要考查了根据课本内容填空的能力，需要熟悉课本中Story time部分的内容，并准确记忆其中的关键表达。题目中给出了关于保持城市清洁的一些做法的句子，其中有部分单词缺失，需要根据课本内容填写完整。
【答案】：
To keep our city clean, we can take the bus or the metro to school. We can't throw the rubbish on the ground and we can put it in the bin. We can plant more trees.
【答案】：
To keep our city clean, we can take the bus or the metro to school. We can't throw the rubbish on the ground and we can put it in the bin. We can plant more trees.
(1) What
(2) Is our classroom
(3) We can
(4) The trees can help
(5) We can
(6) There was a lot of rubbish in the
makes
the river dirty
?(2) Is our classroom
clean
?(3) We can
walk
home.(4) The trees can help
keep
the air clean
.(5) We can
plant
more trees.(6) There was a lot of rubbish in the
water
.答案：【解析】：
这是一道英语填空题，需要根据句意和首字母提示来补全句子。对于这类题目，我们首先要理解句子的意思，然后结合首字母提示，推测出缺失的单词。接下来，我们逐一分析每个句子：
(1) 第一个句子询问的是河流被什么污染，结合首字母m和d，可以推测出是“make”和“dirty”，表示“使变脏”。
(2) 第二个句子询问的是教室是否干净，结合首字母c，可以推测出是“clean”，表示“干净的”。
(3) 第三个句子表示我们可以步行回家，结合首字母w，可以推测出是“walk”，表示“步行”。
(4) 第四个句子表示树木可以帮助保持空气清洁，结合首字母k和c，可以推测出是“keep”和“clean”，表示“保持清洁”。
(5) 第五个句子表示我们可以种更多的树，结合首字母p，可以推测出是“plant”，表示“种植”。
(6) 第六个句子表示水里有很多垃圾，结合首字母w，可以推测出是“water”，表示“水”。
【答案】：
(1) What makes the river dirty?
(2) Is our classroom clean?
(3) We can walk home.
(4) The trees can help keep the air clean.
(5) We can plant more trees.
(6) There was a lot of rubbish in the water.
这是一道英语填空题，需要根据句意和首字母提示来补全句子。对于这类题目，我们首先要理解句子的意思，然后结合首字母提示，推测出缺失的单词。接下来，我们逐一分析每个句子：
(1) 第一个句子询问的是河流被什么污染，结合首字母m和d，可以推测出是“make”和“dirty”，表示“使变脏”。
(2) 第二个句子询问的是教室是否干净，结合首字母c，可以推测出是“clean”，表示“干净的”。
(3) 第三个句子表示我们可以步行回家，结合首字母w，可以推测出是“walk”，表示“步行”。
(4) 第四个句子表示树木可以帮助保持空气清洁，结合首字母k和c，可以推测出是“keep”和“clean”，表示“保持清洁”。
(5) 第五个句子表示我们可以种更多的树，结合首字母p，可以推测出是“plant”，表示“种植”。
(6) 第六个句子表示水里有很多垃圾，结合首字母w，可以推测出是“water”，表示“水”。
【答案】：
(1) What makes the river dirty?
(2) Is our classroom clean?
(3) We can walk home.
(4) The trees can help keep the air clean.
(5) We can plant more trees.
(6) There was a lot of rubbish in the water.
3. 连词成句。
(1) metro, school, to, can, we, take, the
We can
(2) from, air, dirty, cars, smoke, made, the
(3) to, do, can, our, clean, keep, what, we, streets (?)
(1) metro, school, to, can, we, take, the
We can
take
the metro
to school.(2) from, air, dirty, cars, smoke, made, the
Dirty smoke
from cars made
the air
dirty
.(3) to, do, can, our, clean, keep, what, we, streets (?)
What can we do to keep our streets clean?
答案：(1) take; metro
(2) Dirty smoke; made; air dirty
(3) What can we do to keep our streets clean?
(2) Dirty smoke; made; air dirty
(3) What can we do to keep our streets clean?
A: Look at the rubbish in this old photo.
It made our city
B: What can we do to
A: We can
It made our city
dirty
.B: What can we do to
make our city clean
?A: We can
put the rubbish in the bin
.答案：dirty; make our city clean; put the rubbish in the bin