Question

高中英语···

the scientist and technicians overcame a lot of difficulty----the personal computer.
A.they developing B.they had developed
答案选A额···谁能帮我解释一下啊···拜托啦～：）

Answer 1

答案A少个had吧，如果是这样，我帮你分析这个题目：主语the scientist and technicians 谓语overcame 宾语a lot of difficulty they had developing the personal computer.为省略关系代词that的定语从句修饰a lot of difficulty 。that指代difficulty，转化为单句：they had a lot of difficulty （in）developing the personal computer。
供你参考。

Answer 2

这脱胎于have difficulty （in）doing sth.这个词组overcame就相当于对have的否定

Answer 3

they与the personal computer是主动关系，所以选先在进行时