33. of the day, of a day

of the day每一天的,当时的,当代的;
of a day暂时的,不长久的 eg:a famous scientist of the day

34. three of us, the three of us

three of us我们(不止三个)中的三个;
the three of us我们三个(就三个人)eg:The three of us---Tom, Jack and I went to the cinema.

35. by bus, on the bus

by bus表手段,方式,不用冠词;
on the bus表范围 eg:They went there by bus.

36. for a moment, for the moment

for a moment 片刻,一会儿;
for the moment暂时,一时 eg:Thinking for a moment, he agreed.