挑战习题
1/5单选题
难度:

1.函数的定义域为()
A
B
C
D
提示1:
5Zug5Li65pyJPGltZyB3aWR0aD0xNyBoZWlnaHQ9MjEgc3JjPSJodHRwczovL3AyLnFpbmdndW8uY29tL0cxL00wMC84RC81My9yQkFDRTFQWjhUT1FFaGF4QUFBQmVFN0FGb2c2MzAucG5nIj4s5omA5LulPGltZyB3aWR0aD0yMiBoZWlnaHQ9MjEgc3JjPSJodHRwczovL3AyLnFpbmdndW8uY29tL0cxL00wMC84RC81My9yQkFDRTFQWjhUT0MtOVc3QUFBQlB6M2lZc0EzNjAucG5nIj4w77yM5Y+I5Zug5Li6PGltZyB3aWR0aD0zMiBoZWlnaHQ9MjEgc3JjPSJodHRwczovL3AyLnFpbmdndW8uY29tL0cxL00wMC80Ri9ERC9yQkFDRkZQWjhUUHp0OXQ4QUFBQlJpNG9sNnM0ODgucG5nIj7kvZzkuLrliIbmr43vvIzliIbmr43kuI3og73nrYnkuo4w77yM5omA5LulPGltZyB3aWR0aD0zNCBoZWlnaHQ9MjEgc3JjPSJodHRwczovL3AyLnFpbmdndW8uY29tL0cxL00wMC84RC81NC9yQkFDRTFQWjhUUFNON3ZUQUFBQlozSmFxcWMwNjMucG5nIj4=
正确答案:Qw==
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