.Even today I still remember the great fun we had ________ games on the beach on those happy days.
It is a long time ________ they separated, but it won’t be long ________ they meet again.
_______ his scientific work, he has no time to care for his family affairs, _______, of course, his wife always complains about.
The silence in the dark building was scaring. No sound and voice____ heard at that moment.
If _____ without following the doctor’s instructions, the medicine may have serious side effects.
________ you happen to see Mary, would you please ask her to come here?