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     What do you know about a robot? Robots are machines that can be made to do certain things. They

are in all shapes. For example, puppy (a young dog) robots    1    like real ones. They jump and bark (吠).

Robots can do many    2    people can't do. Robots can go where people can't go and bring back important

information. In 1997, scientists sent a robot to Mars. It    3    pictures of rocks and soil, which helped

scientists understand    4    0ur own planet works. Scientists even used a robot to make a    5    of a

volcano. So robots are very    6    machines. They play a very important    7    in our life. They help people

understand the world we live in.

1._____ 2._____ 3._____ 4._____ 5._____ 6._____ 7._____

与0.2mol/Ｌ的HCl溶液100mL，氢离子浓度相同的溶液是（）。

A、0.2mol/l的H₂SO₄溶液50mL

B、0.1mol/L的HNO₃溶液200mL

C、0.4mol/l的醋酸溶液100mL

D、0.1mol/L的H₂SO₄溶液100mL