RT.最近开学在复习中.碰到了一些问题.

RT.最近开学在复习中.碰到了一些问题.
1.A bullet hit the soldier and he was wounded in ___leg
A.a B.one C.the D.his
但是不明白为什么.是不是后面是固定搭配?还是别的?
2.The cakes are delicious.He'd like to have___third one because_____second one is rather too small.
A.a;a B.the;the C.a;the D.the;a
这个完全不懂了.为什么不全是the呢?明明都是序数词
3.One way to understand thousands of new words is to gain_________good knowledge of basic word formation.
A./ B.the C.a D.one
有些不太懂题目的意思.
4.On _________news today,there were_______reports of heavy sonw in that area.
A.the;the B.the;/ C./;/ D./;the
这个题型没看到过.希望教我怎么做这一类的.
5.As a rule,domestic servants doing odd jobs are paid__________
A.by the hour B.by hour C.by an hour D.by hours
为什么不是B?按小时计算到底怎么表示呢?
不多.我先问5句吧.希望快点有回答.