My answers to Sentence 1 and 2 are B.
First the language, then the question.
B fits 1 very well, since the context demands that not only do the events need sequencing, which is what the perfect aspect does, but also that there ought to be a logical implication that the second action is dependent on the completion of the action of the first clause. You can think of it as meaning 'due to the fact that his problems in Africa had been solved, it was now possible for him to return to his homeland'. A also fits logically in 1 but less well. The logic is simpler there, being just that one event followed another.
For question 2, the now added time phrase 'since 2003' in my opinion does nothing useful for the question. B is still better than A, but now neither sentence works as well, the added time phrase doesn't fit, the logic is disrupted, and hence the question is no good. I might guess that the question writer believes that inserting the 'since'-phrase in some way forces B, but I don't think that's quite right.
From the way you've presented the question, I would presume that the question setter is instructing you not to use the same answer for both questions, and that both answers must be used. Again, if that's the case, the question fails.
According to my knowledge obtained from the grammars published by Chinese linguists, when we are talking about the use of present participle of a verb, and if it(‘overcome’ here) occurs before another(‘return’ here), the perfect form of present participle of the first action should be adopted to highlight the chronological order.
That's not entirely correct, strictly speaking. First, the perfect aspect is
not necessary to sequence the verbs, though it does usually help very much to do so. Second, the perfect aspect does more than merely sequence events—it also casts a retrospective aspect, which carries an emphasis on completion. This emphasis usually expresses the logical relation between two states or actions, whatever that relation may be.
But there also are some exceptions, one of which is listed below.
(v) Returning to London, Howard developed his design in the 1880s and 1890s, drawing on ideas that were popular at the time, but creating a unique combination of designs.
This isn't an exception. The perfect form 'having returned' is also possible here, with a different logic.
For (v), the verb ‘return’ takes place before ‘develop’, why returning instead of having returned is used here?
In both of the following sentences the sequence of events is the same:
(a)
Returning to London, Howard developed his design in the 1880s and 1890s ...
(b)
Having returned to London, Howard developed his design in the 1880s and 1890s ...
The difference is in the meaning, i.e., in the
aspect that is cast. Sentence (a) lacks the perfect aspect, which in (b) places an emphasis on the
completed nature of the returning and what that entails. In this particular context, such emphasis is not necessary, so the simple sequencing logic of sentence (a) suffices. It's just one thing following another. As I said above, the perfect aspect is sufficient but not necessary for sequencing, and it does more than just that.
To Sentence 3, my answer is B.
No, B is wrong for question 3. The answer is A.
Think of the sentence in a full conditional form:
[
If they had been]
Given more attention, the trees could have grown better.
This is a past hypothetical. The idea is that the trees did not grow very well but they could have in a past possible world. Using B for 3 would be incoherent, as the phrase 'Having been given' would relate to a real past whereas 'could' in the other clause would relate to an unreal past, and that wouldn't make sense.
(vi) If the trees had been given more care, they could have grown better.
Yes, you've understood it correctly. The 'if'-clause shows an unreal past.
This sentence involves subjunctive mood. From my personal view, the predicate of the conditional clause is ‘had been given’, so if I have to abbreviate it in particle form, B is better.
No, B is wrong. The answer is A, which is also in the same participle form.
The last one comes from Wechat.
4. The guy repairing that Ford is an engineer. (What does the underlined part indicate?)
A. The guy is repairing that Ford.
B. The guy has repaired that Ford.
Only A makes sense. There is no way that a reduced -
ing phrase can carry the perfect aspect as it can the progressive.
[For full answers, ask just one question at a time, please!]