✔ 最佳答案
Errors and corrections:-
(A)participial phrase/phrase containing a gerund:-
=On arriving at his office(=arriving)
used only adjectivally to describe the subject"He'is Okay.
(B)The past perfect tense here means
=When two actions happened in the past one after another, we use the past perfect tense for the first action.
=had arrived office------turned----checked
=wrong by putting at the end of sentence; unless all use the simple past tense throughout for sequence of tense is Okay !
hence A is correct, while B is incorrect.
2015-05-09 02:20:06 補充:
propoesed amendment:-(A) he-subj=arriving be used in Inverted sense=On arriving.(B) as soon as he was arriving by putting at end.