How are the kids spending their childhood? I can’t help recalling(回忆)that there was a time _______ we played happily and freely in the outside.
His _____ expression suggests that the news he read just now must be _____.
It is _____ that Professor Smith will give us a lecture tomorrow.
_______ his research, man can set foot on the moon now.
The rest of the apple _________.
Only when his mother arrived ___________.