【導(dǎo)讀】CaughtbyablackholeThespaceshipwarnedLiYanpingandmetobereadyaswewereapproachingthe“blackhole”.Wecouldseesomefaintlightsaroundwhatlookedlikeanemptyspace.LiYanpingsaid,“Thatemptyholeislikeamouthalwaysneedingtobefed.Thoselightsarethinsthatarebeingpuledintotimebythegravityofthehole.”Wewatchedwithinterestandamazementatthelightswhichseemedtobegoingfainterandfainterroundtheedgeoftheblackhole.Justthenthelightsonourspaceshipwentourtheandtheputerstopedworking.Whatwashapening?

　　

【正文】 shi p cabi n watchi ng the earth be e sm al ler and the m oon l arger. When we got there, I wanted to expl ore i mm edi atel y. “ Com e on, ” I sai d. “ If you are ri ght, m y m as wi l be l ess than on the earth because the m oon is sm al l er and I wi l be abl e to m ove more freely. I m ight even grow tal er i f I stay here l ong enough. I shal certai nl y wei gh l ess!” I laughed and cl im bed down the steps from the spaceshi p. But when I tri ed to step forward, I found I was carri ed twice as far as on the earth and fel over. “ O h dear, ” I cried, “ wal ki ng does need a bit of practi ce now that gravi ty has changed. ” After a whi l e I got the hang of i t and we began to enjoy oursel ves. Leavi ng the m oon?s gravi ty was not as pai nful as l eavi ng the earth?s. But returning to the earth was very fri ghteni ng. We watched, amazed as fi re broke out on the outsi de of the spaceshi p as the earth?s gravi ty i ncreased. Agai n we were pushed back hard i nto our seats as we cam e back to l and. “ That was very exhausti ng but very exci ti ng too,” I sai d. “N ow I know m uch m ore about gravi ty! Do you thi nk we coul d bi si t som e stars next tim e?” “O f course, ” he smi led, “ whi ch star woul d you li ke to go to?” Caught by a black hol e The spaceshi p warned Li Yanpi ng and m e to be ready as we were approachi ng the “bl ack hol e”. We coul d see som e fai nt l i ghts around what l ooked li ke an em pty space. Li Yanpi ng sai d, “ That em pty hol e i s l ike a m outh al ways needi ng to be fed. Those l ights are thi ns that are bei ng pul ed i nto ti me by the gravi ty of the hol e. ” We watched wi th i nterest and am azem ent at the l i ghts whi ch seem ed to be goi ng fai nter and fai nter round the edge of the bl ack hol e. Just then the l ights on our spaceshi p went our the and the puter stoped worki ng. What was hapeni ng? I tri ed to turn the spaceshi p away from the hol e but it woul d not m ove. Woul d i t eat us too? Suddenl y the spaceship jum ped and began to m ove round the edge of trhe hole to. The gravity of the “bl ack hol e” was pul li ng us i nto its “m outh”. As the spaceshi p m oved round the bl ack hol e, I fel t rather si ck. My m outh went dry and I cl osed m y eyes. Al l the stori es about what happened when you were caught by the gravi ty of a “bl ack hol e” seem to be true. But then the spaceshi p jum ped agai n. Thi s tim e i t m oved si deways and away from thi s edge of the “bl ack hol e”. Som eone watchi ng m e woul d have seen the spaceshi p flyi ng li ke a bi rd away from the “bl ack hol e”. But we fel t nothi ng. At l ast we were abl e to l ook around us. Luckil y the puter had started worki ng agai n. We real i zed that we had di scovered som ethi ng new about “black hol e”. If you go insi de the edge of a “bl ack hole”, i t wi l “eat” you and there i s no escape。 but i f you do not, you m ay have an opportunity to escape. H ow exci ti ng! Uni t 5 A tri p on “ The True North” Li Daiyu and her cousi n Liu Qi an were on a tri p to Canada to bi si t thei r cousins i n Montreal on the Atl anti c coast. Rather than take the aeropl ane al l the way, they deci ded to fl y to Vancouver and then take the trai n west to east acros Canada. The though that they coul d cross the whol e conti nent was exciti ng. Thei r fri end, Danny Lin, was wai ti ng at the ai rport. H e was goi ng to take them and thei r baggage to catch “The True N orth”, the cross Canada trai n. O n the way to the stati ion, he chatted about thei r tri p. “You?re goi ng to see som e great scenery. Goi ng eastward, you?l pass m ountai ns and thousands of l akes and forests, as wel l as wi de ri vers and l arge ci ti es. Som e peopl e have the i dea that you can cros Canda i n l ess than fi ce days, but they fet the fact that Canada i s 5500 kil om eters from coast to coast. H ere i n Vancouver, you?re i n Canada?s warm est part. People say i t i s Canada?s m ost beautiful ci ty, surounded by m ountains and the Paci fi c O cean. Ski i ng i n the Rocky Mountai ns and sail i ng i n the harbour m ake Vancouver one of Canada?s m ost popul ar ci ti es to l ive i n. Its popul ati on i s i ncreasi ng rapi dl y. The coast north of Vancouver has som e of the ol dest and m ost beauti ful forests in the worl d. It i s so wet there that the trees are extrem el y tal l, som e m easuri ng over 90 m etres.” That afternoon aboard the trai n, the cousi ns settl ed down i n thei r seats. Earli er that day, when they crossed the Rocky Mountai ns, they m anaged to catch si ght of som e m ountai n goats and even a gri zzl y bear and an eagl e. Thei r next stop was Cal gary, whi ch is fam ous for the Cal gary Stam pede. Cowboys from al l over the worl d e to pete i n the Stampede. Many of them have a gi ft for ri di ng wil d horses and can wi n thousands of dol ars i n pri zes. After two days? travel, the gi rls began to real ize that Canada i s qui te em pty. At school , they had l earned that m ost Canadi ans l i ve withi n a few hundred ki lom etres of the USA border, and Canada?s popul ati on i s onl y sli ghtly over thi rty m il li on, but now they were am azed to see such an empty country. They went through a wheatgrowing provi nce and saw farm s that covered thousands of acres. Afrer di nner, they were back i n an urban area, the busy port city of Thunder Bay at the top of the Great Lakes. Because of the Great Lakes, they l earned, Canada has m ore fresh water than any other country in the worl d. In fact, i t has onethi rd of the worl d?s total fresh water, and m uch of it i s i n the Great Lakes. That night as they sl ept, the trai n rushed across the top of Lake Superi or, through the great forests and southward towads Toronto. “The True North” from Toronto to Montreal The next m orni ng the bushes and m apl e trees outsi de thei r wi ndow were red, gol d and orange, and there was frost on the ground, confirmi ng that fal l had arrived i n Canada.