1.答案：A.
2.翻譯：說(shuō)到成功,我并不是想指當(dāng)這個(gè)字眼(即成功)被提到時(shí),而通常被(人們所)想到的含義.
3.
1）固定短語(yǔ)：mean A by B 說(shuō)到B時(shí)所指的含義
如：What do you mean by that?你說(shuō)到那(個(gè)東西),
該題把by B(success)提前到句首了.
2）短語(yǔ)中的A即題中的what is usually thought of when that word is used.這是一個(gè)含有when引導(dǎo)的時(shí)間狀語(yǔ)從句的名詞性從句（確切地說(shuō),是mean的賓語(yǔ)從句）.
至于該賓語(yǔ)從句的意思,是指“當(dāng)那個(gè)字眼被用及時(shí),通常被想到的（意思/含義）”.
3）該賓語(yǔ)從句中的what is,做該從句的主語(yǔ)和系動(dòng)詞.這樣從句的結(jié)構(gòu)才能完整：what is ususally thought of (when that word is used).