几题英语完成句子,懂英语的朋友来解答下,

几题英语完成句子,懂英语的朋友来解答下,
6.is it true that only when Tom fully recovered____(他才回去）to work?(go)
7.there musu have been an old temple at the foot of the hill50 years ago___(是吗)?(be)
8.___(知道）to everybody,the moon travels round the earth once every month (know)
10.noisy as it is,he is reading attentively as if___(没事在发生）（happen）