just用于现在完成时可以理解了,但是能不呢过用于过去式呢?

just用于现在完成时可以理解了,但是能不呢过用于过去式呢?
我见有的答案说just用于完成时表示对现在的影响.
但是还是没有根本说明到底just能不能用于过去式.
比如：i have just received a letter from my brother,tim.
能否：i just received a letter from my brother ,tim.
i have just had breakfast
i just had breakfast.
有时候不知道是不是错误的感觉,总觉得说话的时候会说i just+过去式,所以问题就是到底just能不能和过去式一起用呢,还是过去式只能用just now.
因为百度有的答案里面有人写了just+过去式.让人很费解,大家说的都不一样.
另外新概念英语第二册4课主要就是联系have just xxxxxx.
课文中出现的是have just,课后一道练习题是照搬课文的填空,可是把just前面的填空都删掉了.
课文：i have just received a letter from my brother,tim.he is working for a big firm and he has already visited a great number of different places in Australia.He has bought an australian car and has gone to Alice springs.my brother has never been abraod before.
练习题没有答案,用括号中正确形式填空,完成后对照课文,核对你的答案：
不知道为什么要删掉所有的have,我自己只好把词改为过去式.但是感觉很奇怪.
特别是already,never那儿没有用have.
i just______(receive) a letter from my brother,tim.he is working for a big firm and he already______(visite) a great number of different places in Australia.He just______(buy) an australian car and ______(go) to Alice springs.my brother never______(be) abraod before.
这里把课文里面的have全部删掉了 真的就用过去式了吗?这样对吗
如果用过去式的话,那就说明just可以直接加过去式了?

just后可以加过去式,表示过去发生的事,你可以理解为“就”.如,---you threw your t-shirt?(惊讶)---yeah,I just did it.
i just______(receive) a letter from my brother,tim.he is working for a big firm and he already______(visite) a great number of different places in Australia.He just______(buy) an australian car and ______(go) to Alice springs.my brother never______(be) abraod before.
上面这段,一定要分析出来现在的事情是he is working for a big firm,收到信和他已经去过很多地方用and连接,是同一个时态,收到信是过去的动作,而且作者没有强调对现在的影响,所以两处都用过去时.最后一个空,本可以用had never been,但是有before,而且跟前面的时态保持一致,所以也是过去式.
再问： 老师，请问两个句子之间有and连接，前面一个句子和后面一个句子要用一样的时态吗？？但是原课文中有.he is working for a big firm and he has already visited a great number of different places in Australia. 现在进行时和现在完成时呀？ He just______(buy) an australian car and ______(go) to Alice springs。这句怎么填写呢 bought和 went\has gone to? 谢谢老师！
再答： 不客气哈~可能还要说得不对的地方，英语你多揣摩，多看多读，一定会有进步的。 两个句子之间有and连接，从逻辑上说应该是要相同的时态，但是还是需要看语境、句子要表达的意思，比如有明显的表示时间的词，就会影响到时态。 he is working for a big firm and he has already visited a great number of different places in Australia. 这个你就需要分析了，这里想说：他正在为一部电影工作，而且他已经参观了澳大利亚大量的不同地方。 He just____bought__(buy) an australian car and __went____(go) to Alice springs。(这里就表示两个过去的动作，都用过去时，你不能前面用bought 后面用表示现在的has gone to)