Therearemanyinterestingscienceexperimentsoutthereforyoungkids.Youcansurpriseyourfriendsandteacherswiththem.Allyouhavetodoistoputalittleeffortintoitandyoushouldhavenoproblemcomingupwithanin?terestingscienceexperiment.Onesuchexperimentistoshowyourfriendsandteachersthatyoucanmakemothballs(棒脑丸)dance!Ifyouwanttodoitfirstbesurethatyouhavegotallthenecessarysci?encekitsforyourscienceexperiment.

Whatyouneedforthisexperimentisaglassfilledhalffullwithwater.Addalittlebitofvinegartoyourglassofwaterabout1/3or1/4ofacup(60ml)andoneteaspoon(10ml)ofbakingsodaandthencarefullystirthemix?ture.Dropafewmothballsintotheglassandhaveyouraudiencewatch.Aslongasthesurfacesofthemothballsbecomefairlyroughtheyshouldbegintobounceupanddownintheglass.

Youcanalsodoasimilarexperimentwithraisins(葡萄干)andclearpopsuchasSprite.InthisexperimentallyouhavetodoistofillaglasswithSpriteanddropafewraisinsintoit.TheraisinsshouldbegintobounceupanddownintheglassofSprite.YoucanalsoreplacetheraisinswithmothballsandyoushouldgetthesameeffectintheSprite.ThisprojectworksbecausetheirregularsurfacesofthemothballsandtheraisinsholdsomeC02bubbles(气泡)，causingthemtobounceupanddowninadancingmotion.

1.Thewriterwritesthispassageto .

A.explainwhysomescienceexperimentsareeasy

B.encouragepeopletospendmoretimeonscience

C.tellushowgoodheisatdoingscienceexperiments

D.teachkidshowtodoaneasyandinterestingscienceexperiment

2.Whatisthemostprobablenameoftheexperiment?

A.Producingmothballs.

B.Dancingmothballs.

C.Changingmothballs.

D.Swimmingmothballs.

3.Whichofthefollowingthingsareneededintheexperiment?

a.bakingsoda b.water c.mothballs

d.salt e.vinegar f.sugar

A.beef B.acde

C.abed D.abce

4.Theunderlinedword"pop"inParagraph4 probablyreferstoa .

A.mothball

B.kindofvinegar

C.drinkwithbubbles

D.specialkindofraisin

5.Fromthelastparag