Speaking loudly in public is a kind of behavior(行为), so we should learn to avoid this situation.

Have you ever visited the Opera House?—Yes．When I was in Sydney, I ______ it twice

take acoffee break, shall we–I wish I________, but I have a really tight schedule

So absorbedin theexperiment that he didn’t even notice it was already over 12 o’clock.

The possibility____ pleasant smells might reduce pain has recently been suggested by new research.