一篇完形英语You and your friends cannot run a long way when you’re

一篇完形英语
You and your friends cannot run a long way when you’re hungry,can you?Birds __1__,either.So __2__migration(迁徙),they eat a lot to build fat(脂肪) for energy.Fat can be up to 50 per cent of a migration bird’s ___3__.Migration is __4__for birds.Some have to fly across seas to reach the place where they’re going.Birds usually fly a long way,but they___5__lose their ways.Are you___6__ in what the secrets are?Birds can see clearly and read landmarks(地标).Mountains(山 岳),rivers,even large buildings can be landmarks.They help show them__7__ to fly.Birds can also tell directions(方向) by looking at the sun and stars.They use the North Star to find the north and the sunrise for the___8___.When many birds migrate together,young birds usually__9___the old.They need the old to be in the front and to teach them how to find their wintering(过冬天的) grounds.Migrating birds use all these skills to travel over thousands of __10___each year.( )1.A.can B.can’t C.must D.mustn’t ( )2.A.after B.while C.because D.before ( )3.A.height B.head C.weight D.feathers ( )4.A.interesting B.easy C.impossible D.difficult ( )5.A.sometimes B.always C.often D.seldom ( )6.A.interested B.excited C.sure D.fun ( )7.A.how B.when C.where D.why ( )8.A.west B.north C.east D.south ( )9.A.find B.catch C.look at D.follow ( )10.A.days B.kilometres C.weeks D.clouds(云)

B.can’t
D.before
C.weight
D.difficult
D.seldom
6.A.interested
C.where
C.east
D.follow
B.kilometres