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【简答题】
能源、环境、材料与人类的生活息息相关．根据所学知识回答下列问题． （1）生命之源，保护水资源从我做起． ①电解水试验中，往水中加入少量氢氧化钠的目的是 ，试验时若正极产生6ml气体，则负极产生气体的体积是 ml，该实验证明了由 组成的． ②生活中 来降低水的硬度．如图所示是自制净水器，其中活性炭的作用是 ；制造塑料瓶的材料属于 材料．请介绍一种你的节水方法 ． （2）化石燃料是有限的，大量使用会导致环境污染．请你例举一种清洁能源 ．
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举一反三
【单选题】When I passed by, I heard her _____ in the room.
A.
sings
B.
sang
C.
singing
D.
to sing
【单选题】She_____ cleaning when I passed by her house.
A.
did
B.
does
C.
is doing
D.
was doing
【简答题】When I passed by her room, I heard her ________ (read) aloud an English text.
【单选题】Mary was angry with me and she pretended _____ me when I passed by her. [ ]
A.
not to see
B.
not seeing
C.
to see
D.
not saw
【单选题】Section B Directions: There are 2 passages in this section. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A, B, C and D. You shoul...
A.
affordable printers make it possible for anyone to forge documents
B.
the American Secret Service will be able to trace any document
C.
every printed document will be secretly marked out through high-tech
D.
counterfeiters have more advanced technology to use
【单选题】I saw her flowers in the garden when I passed by.
A.
water
B.
to water
C.
watered
D.
watering
【简答题】I heard the English song ____________( sing) when I passed by her room yesterday.
【单选题】I saw her flowers in the garden when I passed by.
A.
to water
B.
water
C.
watering
D.
watered
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