问题补充:
The old couple are living,for their only son works abroad after graduation.
A. on their own
B. of their own
C. separately
D. particularly
答案:
(答案→)A. on their own
B. of their own
C. separately
D. particularly
解析:“惟一的儿子在国外工作,因此这对老年夫妇独自生活。”on ones own“独自地”;of one’s own“某人自己的”,C、D两项与句意不符。