常见的：It has been about ten years since I arrived in Australia.
所以用Arrived是正确的
但是如果不用动词arrive,而用be,则要说since I have been ...
原句里面的It's about ten years 严格地说应该是 It's been about ten years...It's been = It has been
since 用法
prep./conj.1.自从 2.因为 ad.从那以后
副词 adv.从那时以来
from then until now
· I saw him in June,but we haven't met since.
我在六月见到过他,从那以后我们未见过面.
· He has looked for a job ever since.
他打那一直在找工作.
副词 adv.过去至现在的一段时间
at the same time between then and now
· Mr.Li was ill last week but has since recovered.
李先生上星期病了,后来就痊愈了.
副词 adv.以前；在现在以前
ago; before now
· The word has long since been out of use.
此字老早以前就无人使用了.
· ever since
从那时起一直到现在
· Jack went to Canada in 1974 and has lived there ever since.
杰克于一九七四年去加拿大,从那时起到现在一直住在那里.
连词 conj.从…以来；…以后
from the time when
· What have you been doing since I saw you last?
自从我上次看到你以来,你做什么了?
· He has been in the army since he left school.
他离开学校以来一直在部队里.
· He has devoted himself to teaching since he graduated from the college in 1962.
他一九六二年大学毕业以后一直献身教学工作.
连词 conj.因为；既然
because; as
· Since I have no money,I can't buy any food.
因为我没钱,所以不能买任何食品.
· We don't know much about the appearance of the surface of Antarctica,since it is covered with ice more than two miles thick in some places.
我们对南极洲的地面形状了解不多,因为在这个洲有些地面覆盖着两英里多厚的冰层.
· Since we're League members,we should set a good example to others.
即然我们是团员,我们就应该给别人做个好榜样.
· Since we have no money,it's no good thinking about a holiday.
既然我们没有钱,考虑度假有什么用.
介词 prep.从…以来；自从
in all the time after
· She has been ill since last Sunday.
上星期日以来,她一直在生病.
· He has eaten nothing since yesterday.
自从昨天以来他没吃过东西.
· Since my last letter I have heard from him twice.
自从我上次写信给他以后,我已经收到他两封信了.