After the dinner party, most guests left, with only two of them ______in the host family, ______ him clear up.

Laws should be made______ the terrible haze（雾霾）______harm to our health.

48I will ask my father to telephone you _____ he comes back

Someone called you just now.——I know. But I was busy at that moment. When I calledback, there was no.

The chances of discovering life on Neptuneare about a million _____