It is difficult to understand this kind of _______ calculation.
正确答案： A
本题解析：
参考译文：很难理解这种错综复杂的计算。 intricate 错综复杂的，纠缠不清的; varied 不同的，种种的; indispensable不可缺少的，绝对必要的; equable 变动甚少的，稳定的。
_______ for a long time, most of the crops in this area died from lacking water.
The factory _______ we ’ll visit next week is not far from here.
The new laws threaten to deprive many people _______ the most elementary freedoms.
This is the first time that a woman has been ________ to the post.
He has deep love for the people and ________ loyalty to the country.
I ’ve got the order from the boss that the work _______ finished before 5 p.m. today.
I don ’t think the charge for overhauling the equipment is excessive in _______ to its size.
She ________ everything else and concentrated on the task before her.
______ he has enough money to buy the house, it doesn ’t mean he ’s going to do so