well.
答案：until→if 此处表示“如果我们不断地练习，学好英语口语对我们来说就会很容易”，所以用连词if引导一个条件状语从句。
8. One day, I was cooking in the kitchen as the telephone rang.
答案：as→when be doing...when...“正在做某事，这时……”，是固定句式。 9．Charles Rolls, a car maker, was very interested in Royce's car, but soon Rolls and Royce went into business together.
答案：but→and “很快他们就合作了”是顺承前一句所说的事情发生的，故连词用and。 10．Work hard, you will make much progress and realize your dream.
答案：you前加and 本句是“祈使句＋and＋陈述句”句式，表示“做……，那么你就会……”。
11．(2016·新课标Ⅰ)Though not very big, but the restaurant is popular in our area.
答案：去掉but 句意：餐馆虽然不大，却在我们这个区域很受欢迎。though不和but连用，因though位于句首，故去掉but。
12．(2016·新课标Ⅰ)Every day he makes sure that fresh vegetables or high quality oil are used for cooking.
答案：or→and 句意：每天他都确保用于烹饪的是新鲜的蔬菜和高质量的油。从句意判断前后是并列关系，故把or改为and。
13．(2016·新课标Ⅱ)If we stay at home, it is comfortable but there is no need to spend money. 答案：but→and 句意：如果我们待在家里，会很舒服而且也没有必要花钱。上下句之间是并列关系，而非转折关系。
14．(2016·四川)Mom has a full－time job, so she has to do most of the housework. 答案：so→but 句意：妈妈做全职工作，但是她得干大部分家务活。前后句之间为转折关系，故应用but连接。
15．(2016·四川)Both Dad or I planned to do something on Mother's Day.
答案：or→and 句意：爸爸和“我”都打算在母亲节这一天做一些事。both...and...“两者都……”，是固定结构，符合语境。