More than two hundred years ago the United States （ ）from the British Empire and became all independent country.

A.got off B.pulled down C.broke away D.drop off

At the party we found that shy girl（ ）her mother all the time.

Scholars and students have always been great travelers. (1). The official case for “academic mob- ility” is now often stated in impressive terms as a fundamental necessity for economic and social pro- gress in the world, and debated in the corridors of Europe，but it is certainly nothing new. Serious students were always ready to go abroad in search of the most stimulating teachers and the most famous academies; in search of the purest philosophy, the most effective medicine, the likeliest road to gold.Mobility of this kind meant also mobility of ideas, their transference across frontiers, their simul- taneous impact upon many groups of people. (2). The point of learning is to share it, whether with students or with colleagues: one presumes that only eccentrics have no interest in being credited with a startling discovery，or a new technique. It must also have been reassuring to know that other people in other parts of the world were about to make the same discovery or were thinking along the same lines，and that one was not quite alone，confronted by inquisition, ridicule or neglect.In the twentieth century, and particularly in the last 20 years，the old footpaths of the wandering scholars have become vast highways.(3) The vehicle which has made this possible has of course been the aeroplane，making contact between scholars even in the most distant places immediately feasible，and providing for the very rapid transmission of knowledge.Apart from the vehicle itself, it is fairly easy to identify the main factors which have brought a- bout the recent explosion in academic movement.(4). Some of these are purely quantitative and re- quire no further mention: there are far more centers of learning，and a far greater number of scholars and students.(5). In addition one must recognize the very considerable multiplication of disciplines，particularly in the sciences, which by widening the total area of advanced studies has produced an enormous num-ber of specialists whose particular interests are precisely defined. These people would work in some i- solation if they were not able to keep in touch with similar isolated groups in other countries.

Parents often faced the（ ）between doing what they felt was good for the development of the child and what they could stand by way of undisciplined noise and destructiveness.

The（ ）colonialists managed to wipe out the entire population.

Beth worked hard to（ ）in with the locals during her visit.