这是一篇VOA新闻，文章链接是：http://www.tingroom.com/voastandard/2016/1/339639.html

以下是截取的相关段落：

1.新闻原句：

Good computer skills are desirable in today's digital age, and playing computer games can help children hone those skills -- as long as they don't overdo it, scientists warn. The British study involved 600 teenagers over a period of two years and found that those who played computer games less than once a week achieved better grades at school than ones who played them twice a day or more often. The study also found that daily use of social media did not affect school performance.

对于绿色句子的黄色部分（频率）进行提问，课本的原句问题是

Q1: According to the news, how often did the British study find that those who played computer games achieved better grades？

我觉得以上对于频率“less than once a week”提问的疑问句不正确，因为这个句子表明的是“英国研究多久发现一次？”。

我自己修改了句子，请老师们看一下是否正确。句子是：

According to the British study, how often did those who achieved better grades play computer games?

此句正确吗？严密吗？？？

2.新闻原句：

Parents increasingly complain of having difficulty getting their children away from computer games. 

课本对这句提出的疑问句是：

Q2: What’s parents attitude toward playing computer games?

请问老师，parents 后面是否需要加一撇（’）变为parents’ attitude? attitude 用单数就可以？toward（美式用法） 和towards（英式用法）都是正确的？

3. 新闻原句:

The games industry has long claimed there is no proven link between games and addiction. 

课本对此句提出的疑问句是：

Q3： What’s the games industry claimed ?

请问疑问句中可以用has的缩写？

非常感谢！！！