4, Though it may be possible to measure the value of material goods in terms of money, it is extremely difficult to estimate the true value of the services which people perform for us.

  in terms of: 按照，就……而言，关于

in respect of

in / with regard to, as regards

5, There are times when we would willingly give everything we possess to save our lives,

 there are times when 有时

6,   yet we might grudge paying a surgeon a high fee for offering us precisely this service.

 grudge后面要和名词或动名词搭配

I grudge wasting time on this.新概念法师

7,   but he will never sacrifice his freedom We often speak of tramps with contempt and put them in the same class as beggars,

with 和名词搭配，表示“具有，带有”

Eg.: How many of us can honestly say that we would like to learn Englsh well?