Do you like tomatoes ______ the sandwiches? [ ]
_____ will you stay there? —For about a month.[ ]
Generally speaking, a computer works _______________ a human brain.
About one third of the population in Beijing and Shanghai ______ netizens, but in poorest areas, only three or four percent ______ online.
We’ll have a hiking trip, but when shall we meet? —Let’s make it ______ half past eight ______ the morning of June 21. [ ]