不接虚拟语气.虚拟语气强调的是 和某个与既成事实不一致的假设.
如：假如我那天没去,我就不会见到他； 假如地球上没有水,生命就不可能存活.等等.假设的部分和其导致的结果均为已发生.
而suppose that则和imagine that的意思较像,意为：想象一下如果xxxx,或者假定xxxx.这里that可以省略,只说suppose就可以.
例如：Suppose (that) this is the most beautiful flower you can find on the earth,then...假如这就是你能在地球上找到的最美丽的花朵,那么.
Suppose that here we have two cubes of different temperature and we bring them together,xxxxx
假设我们现在有两个方块,它们的温度不同,我们把它们放在一起,那么xxxx.
provided that 是既然的意思.
xxxxxx,provided that yyyyy.
既然yyyyy,那么就xxxxx.
就是“既然xxx成立”,“以xxx为条件”的意思,后面接什么时态都行,取决于你要表达什么意思.
例如：
I'll go provided that my expenses are paid.
如果我的费用有人代付,我就去.
I'll come provided( that) I were well enough.
只要我身体好,一定来.
To accept provided that certain condition applies.
如果某种条件满足就可接受.