単数、複数の問題

以下の文章は「データで見る日本」（講談社）からの抜粋です。
The largest number of people have "dogs" as pets.64% of all people who replied that they have a pet at home said they own a dog.

a pet, a dog と単数で処理されている。

NTT DoCoMo's survey shows that 53% of those elementary school pupils and 34% of those junior high school students say" they didn't need a mobile phone themselves, but their parents made them take it."

a mobile phone,it と単数処理されている。

最近この種のことを気にかけています。

参考：文章のはじめは数字の場合スペルアウトしなさいとなっていますが、％がつくものはその限りにあらずのようである。

from today's Nikkei

個と組織　新たな挑戦　効率・意欲　どう両立
働くニホン　現場発　第一部　きしみを超えて　増益なのに伸びぬ給与

Starting from today,we are going to look at the forefront of Japan working on in a series of articles. And in its first instalment titled "overcoming its squeals," we report about the current worklpace conditions.What we want to report first is that Japan,whose people have been working on,is now facing new challenges,which we think are the most serious ever.Although many Japanese companies have recovered from their dificulties getting rid of the old rigid shells made in the period of the so-called "lost 15 yeras," the landscape in the workplace has significantly changed.Amidst the prospects listed companies likely will record their record-high profits for the consecutive fifth year in this busioness year,there seems to be atmospheres in many workplaces that employees have lost their breath and got tired. Therefore,with the principle of capitalism realizing itself,the new problem on how to balance the benifits of the individual and the institution has ocuured.In other word, how to make a balance of efficiency and human will would be a new challenge for Japanese economy.