几道简单的英语选择For a long time they walked without saying a word .

几道简单的英语选择
For a long time they walked without saying a word .Jim was the first to break___silence
为什么要填the?可以不填吗
what will the world use for power when it_____oil?
A run out of B is running out of C has run out of D ran out of
为什么选C,我选的A
scores of,dozend of 后面加可数还是不可数名词啊
问题稍微有点多哈,不好意思