The black teacher set a good example ____ all the rest of the group, _____ all peace-loving people.

to, who are

for, which was

to, which are

to, who were

[翻译]黑人教师给其他所有爱好和平的人树立了一个好榜样。[解析] D 解析：set an example to表示给某人树榜样，由此可以排除B;因先行词指人，故使用who引导非限定性定语从句，由此可以排除C; 根据时态的一致原则可知，此处应当使用一般过去时，故正确答案为D项。

So difficult __________ it to work out the problem that I decided to ask Tom for advice.

 I did find 

did I find

 I have found  

have I found

句子使用的基本句式为so…that…结构。按英语语法，当该结构的so…置于句首时，其后的句子(主句)要用倒装语序，如：So loudly did he speak that even people in the next room could hear him. 他讲话声音那么大，隔壁屋里的人都听得见。

Her father         a writer.

turned

grew

has turned

has become

考查系动词的区别。句意：她的父亲变成了一位作家。Turn，grow，become用作系动词均可表示“变化”，使用时要注意：become主要指一个人暂时性的身心变化或永久性的自然变化，另外还可用于指天气变化和社会的趋势；grow主要表示逐渐变化，强度变化过程；turn后接名词，往往表示意想不到的变化，名词前通常不加冠词。故选D项。

We cannot           the punctual arrival of trains in foggy weather.

get

help

guarantee

guess

考察动词词义辨析。句意：我们不能保证火车在雾天准时到达。A. get得到，获得；B. help 帮助；C. guarantee保证；D. guess猜测。根据句意可知，火车无法保证按时到达。故选C项。