1.Because he was ill yesterday, so he didn’t go to work. (×)
Because he was ill yesterday, he didn’t go to work. (√)
He was ill yesterday, so he didn’t go to work. (√)
[析] 用though, but表示“虽然……，但是…… ”或用because, so 表示“因为……，所以……”时，though和but 及because和so 都只能择一而用，不能两者同时使用。
2.The Smiths have moved Beijing. (×)
The Smiths have moved to Beijing. (√)
