单选题 No one helped me. I did it all ______ myself.

【正确答案】 C

【答案解析】考查固定搭配。(all) by oneself是固定搭配，指“独自，全凭自己”，与前面的No one helped me相呼应。for oneself指“为自己”；from与to一般不与oneself连用。