ex : I am used to _________ up watching TV.

(A) stay　(B) staying　(C) stayed　(D) stays

李捷這麼說：be used to 這個片語中的to 是介係詞，所以後面必須接上名詞或動名詞。所以本題的答案就是(B) staying

※ 文法焦點 : 動名詞當受詞 ( 動詞之後 ) : 有些動詞之後再接動詞時, 此動詞須用動名詞。 此類動詞如下：

enjoy, avoid, finish( =get through ), mind, admit, deny, practice, suggest, appreciate, be worth, postpone( = put off ), escape, quit, imagine, fancy, pardon, resent, hinder, confess, keep(on), repent of, give up, delay, consider, anticipate, resist, risk, miss, discuss( = talk about ), mention, advise, can’t help, feel like, put off, insist on, object to, burst out, recall, be opposed to, recollect, recommend, tolerate, complete, be used (adjusted = accustomed, adapted) to, look forward to, with a view to, with an eye to, thanks to, devote oneself to (= be devoted to ), for the purpose of, owing to, take to, have an(no) objection to ………

ex : We are looking forward to seeing you soon.

此處的to為介係詞，故其後須接動名詞(Ving)。

ex : That museum is well worth visiting if you have time.