请看这道选择题，不要以为to后面一定接动词原形：
Not only should you get used ______ under difficult conditions but you also you pay more attention ______ your work well.
A. to work, to do B. to working, to doing
C. to work, to doing D. to working, to do
【答案分析】正确答案为B，因为 get used to与pay attention to 这两个结构中的to均为介词，不是不定式符号，故后接动词时要用动名词，不能用动词原形。
【类似归纳】
类似地，以下各结构中的 to 也是介词，不是不定式符号，后接动词时也应用动名词，而不是动词原形：
look forward to doing sth 盼望做某事
be opposed to doing sth 反对做某事
object to doing sth反对做某事
stick to doing sth 坚持做某事
get down to doing sth 开始做某事
take to doing sth 喜欢上做某事
admit to doing 承认做了某事
pay attention to doing sth 注意做某事
devote one’s time to doing sth 把某人的时间用于(奉献于)做某事
be equal to doing sth 等于做某事，能胜任做某事
What do you say to doing sth 你认为做某事怎么样