The key answer of exercise 4

1

1. ... that were giving tourists rides.
2. ...,which should have been breeding at that time of year, ...
3. ..., which were being observed by US biologists, ...
4. ... that inhabit an Indian nature reserve, ...
5. ... which can do this job.
6. ..., whose noses don't work well ..
7. ... which we rely on ...

2

• defining relative clauses → a, d, e, g
• non-defining → b, c, f

3

• defining

4

• before and after the non-defining relative clause

5

• g) The preposition goes at the end → ... something which robots are not as good at. In more formal English, the preposition can go at the beginning (at which robots are not as good).

6

• Of course there are already robots which can do this job, one of which looks and moves like a snake...
• The words all, some, few, one, none, either, neither of which can all come before of which.