關於一個英文句型問題。?

The last thing (that) I wanted to do was (to) see a dentist.
本句主詞補語用的是「無to的不定詞」，有尚未發生的意思，如果改用「動名詞」則是已發生或正在發生，不符時序邏輯：那時計畫要做但尚未做的事。

我是認為以下3種寫法都是可以的:
1. The last thing I wanted to do was see a dentist .
2. The last thing I wanted to do was to see a dentist .
3. The last thing I wanted to do was seeing a dentist .

1 與2是一樣的.因為1是2省去to而得來的.

3用現在分詞來表示一般經驗.

例如說:
(A) the last thing I want is receive email from her. 是希望以後不要再收到他的電郵
(B) the last thing I want is receiving email from her. 是表達收到他電郵的痛苦經驗

The last thing I wanted to do was see a dentist. "The last thing" is the subjective phrase which was modified by " I wanted to do was",while "see" being the predicate and "a dentist" the objective phrase. In addition, "I wanted to do was" equals to " I was wanted to do". Yip