It is reported that some mainland visitors to Hong Kong Disneyland didn't _______ the park rules and behaved improperly.

Our government should ____ stricter measures to make sure all food products meet the quality standards.

mankind  

I can meet you at eight o'clock; _____ you can call for me.

In view of all sorts of rumors and guesses, experts carried out some careful and scientific research and         the possibility of a second earthquake in this area.