39.【解析】throughout。從空格后的逗號(hào)后面是一個(gè)完整的句子可以判斷所填詞應(yīng)該是介詞。空后的 its history及 the country has welcomed … from all over the world, most of whom have needed to learn English中兩處用的現(xiàn)在完成時(shí)起提示作用。

　　40.【解析】immigrants。所填詞作welcomed的賓語(yǔ)，并且這些人是來(lái)自世界各地，他們中的大多數(shù)都需要學(xué)英語(yǔ)。

　　41.【解析】experienced。從and可以判斷所填詞和qualified構(gòu)成并列關(guān)系，因此所填詞應(yīng)為一形容詞，概念上與qualified相近，共同修飾teachers。

　　42.【解析】overseas。所填詞修飾students，因此應(yīng)該為一形容詞。空前的from allover the world起提示作用。

　　43.【解析】enroll。所填詞作who的謂語(yǔ)，并且與students在數(shù)上一致，故應(yīng)填一原形動(dòng)詞，并且此動(dòng)詞和介詞on搭配。

　　44.【答案】Most of these institutions provide preparation courses for students who need to improve their English before they start university study

　　【Main Points】Students who need to improve their English before they start university study can take preparation courses in these universities and colleges

　　45.【答案】they are the most common type of courses taken by overseas students

　　【Main Points】overseas students usually take these courses

　　46.【答案】the chance to get to know the school where they will be studying and become more familiar with the American academic environment

　　【Main Points】the chance to know their school and the American academic environment