4. This student has seen being physically fit as an end rather than the means we know it to be.
see sth. as意思是“把…看作为”，我们以前学过不少类似的短语，如：regard…as，look upon…as，think of…as，view…as等等。

being physically fit意思是“身体健康”。

an end rather than the means意思是“是一种目的而不是达到目的的方法”。 rather  than意思是“而不是”。

1）He was seen as the most capable person in the company.（人们认为他是公司最能干的人。）

2）We saw her silence as consent.（我们把她的沉默看作为同意。）

3）To be physically fit is our greatest wish for grandfather.（身体健康是我们对爷爷的最大希望。）

4）You need to do more exercise if you want to be physically fit.（如果你想身体健康，就需要进行更多的锻炼。）

5）He came all the way to China for promoting friendship rather than for making money.

（他千里迢迢来到中国不是为了赚钱，而是为了增进友谊。）

5. His opinion is one of the many feelings， pro or con， that people hold about their personal involvement in a physical fitness program.

pro和con在本句中作形容词用，pro的意思是for（赞成），con的意思是against（反对）。pro or con在句子中作后置定语，修饰名词feeling.后置定语在英语中也很常见。如：

1） Countries， big or small， should be equal.（国家无论大小都是平等的。）

2） He studied in a room， clean and tidy.（他在干净整齐的房间里学习。）

（在上述例句中，两个成对的或反对的形容词，用and或or连接，共同修饰一个名词。这是形容词作后置定语的一种用法。）

1）The active involvement of thousands of people in the election campaign surprised him.

（成千上万的人积极参与竞选活动令他惊奇。）

2） He avoids involvement in politics.（他避免卷入政治。）

6. Certainly some of there individuals may have physical limitations that make activity extremely difficult， and others are engaged in time-consuming activities that until finished do not permit opportunities for recreation.

that make activity extremely difficult是一个定语从句，修饰physical limitations.

Be engaged in sth. 意思是be involved in sth.（使从事，使忙于），如：

1）They were engaged in the study of soil conservation.（他们在从事土壤保持的研究。）

2） It is inappropriate for him to engage in this activity.（他从事这一活动是不合适的。）

7.…I'll have no difficulty staying that way.

have （no） difficulty doing sth.（做某事有/无困难），也可以用have （no） trouble doing sth.。如：

1）He has no difficulty understanding the Chinese film.（看懂那部中国电影他没有困难。）

2）I had a lot of trouble getting back to sleep after I answered the phone call.（接过电话后，我无法再入睡。）

8.…you may have made a commitment to a physical fitness program that might be rather narrow in scope.

make （a） commitment to 意思是make a firm promise（作出承诺），或者involvement（投入）。

Narrow in scope意思是范围很窄，很狭隘。我们接触过在形容词后面加介词in再加名词的机构，如similar in appearance（外表相像）。

9.What could I achieve if I were really in top physical condition？

本句中用