1/5单选题
难度：
1.下列各式成立的是（）
| A |  |
| B |  |
| C |  |
| D |  |
- 提示1：
- PGltZyB3aWR0aD01OSBoZWlnaHQ9MjEgc3JjPSJodHRwczovL3AxLnFpbmdndW8uY29tL0cxL00wMC9BQS8yOC9yQkFDRkZUSW1UT2k0REtGQUFBQjZSRFZLN0U3MzMucG5nIj7kuozmrKHmoLnlvI/nmoTpnZ7otJ/mgKc=
- 提示2：
- PGltZyB3aWR0aD00MyBoZWlnaHQ9NDIgc3JjPSJodHRwczovL3AxLnFpbmdndW8uY29tL0cxL00wMC8zRS9BQS9yQkFDSmxUSW1UUGpXS3RPQUFBQ0JkcG5adVE0MjgucG5nIj49PGltZyB3aWR0aD0xNSBoZWlnaHQ9MjEgc3JjPSJodHRwczovL3AxLnFpbmdndW8uY29tL0cxL00wMC8zRS9FOC9yQkFDSjFUSW1UT3pMU3I2QUFBQlNqNkU4aVkwNjcucG5nIj4=
正确答案：Qw==
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
2/5单选题
难度：
2.
如果等式
成立，那么a必须满足的条件是（）
| A | a为有理数 |
| B | a为实数 |
| C | a为正数 |
| D | a为非负数 |
- 提示1：
- PHA+PGltZyBzcmM9Imh0dHBzOi8vcDIucWluZ2d1by5jb20vRzEvTTAwLzNFL0FBL3JCQUNKbFRJbVlDQy1kbWJBQUFCNldld0NBazYxOC5wbmciIGRhdGEtY2tlLXNhdmVkLXNyYz0iaHR0cHM6Ly9wMi5xaW5nZ3VvLmNvbS9HMS9NMDAvM0UvQUEvckJBQ0psVEltWUNDLWRtYkFBQUI2V2V3Q0FrNjE4LnBuZyIgaGVpZ2h0PSIyMSIgd2lkdGg9IjU5Ij7kuozmrKHmoLnlvI/nmoTpnZ7otJ/mgKc8L3A+
- 提示2：
- PHA+PGltZyBzcmM9Imh0dHBzOi8vcDEucWluZ2d1by5jb20vRzEvTTAwLzNFL0U4L3JCQUNKMVRJbVlDaUxib25BQUFDSG9qWXliODMyOC5wbmciIGRhdGEtY2tlLXNhdmVkLXNyYz0iaHR0cHM6Ly9wMS5xaW5nZ3VvLmNvbS9HMS9NMDAvM0UvRTgvckJBQ0oxVEltWUNpTGJvbkFBQUNIb2pZeWI4MzI4LnBuZyIgaGVpZ2h0PSI0MiIgd2lkdGg9IjYzIj7vvIxh5Li66Z2e6LSf5pWwPC9wPg==
正确答案：RA==
PHA+6Kej562U77ya4oi1PGltZyBzcmM9Imh0dHBzOi8vcDIucWluZ2d1by5jb20vRzEvTTAwLzNFL0FBL3JCQUNKbFRJbVlEamlqY05BQUFDa1NFa1pidzQ3OC5wbmciIGRhdGEtY2tlLXNhdmVkLXNyYz0iaHR0cHM6Ly9wMi5xaW5nZ3VvLmNvbS9HMS9NMDAvM0UvQUEvckJBQ0psVEltWURqaWpjTkFBQUNrU0VrWmJ3NDc4LnBuZyIgaGVpZ2h0PSIzMiIgd2lkdGg9Ijc3Ij48YnI+4oi0YeS4gOWumuS4uumdnui0n+aVsDxicj7mlYXpgIlEPC9wPg==
3/5单选题
难度：
3.如果
和
都是二次根式（x≠0，y≠0），那么x和y的符号应为（）
和都是二次根式（x≠0，y≠0），那么x和y的符号应为（） | A |  |
| B |  |
| C |  |
| D |  |
- 提示1：
- 5LqM5qyh5qC55byP6KKr5byA5pa55pWw5LiA5a6a5piv6Z2e6LSf5pWw
正确答案：Qw==
6Kej562U77ya4oi1PGltZyB3aWR0aD0zNyBoZWlnaHQ9MjUgc3JjPSJodHRwczovL3AxLnFpbmdndW8uY29tL0cxL00wMC8zRS9FOC9yQkFDSjFUSW1ZUFIxM0EwQUFBQnBVRGxPRU0yODIucG5nIj7lkow8aW1nIHdpZHRoPTQyIGhlaWdodD0yNSBzcmM9Imh0dHBzOi8vcDEucWluZ2d1by5jb20vRzEvTTAwLzczLzFFL3JCQUNFMVRJbVlPeUxwZU9BQUFCbmpPRkpyTTkyOC5wbmciPumDveaYr+S6jOasoeagueW8j++8iHjiiaAw77yMeeKJoDDvvIk8YnI+4oi0LXh5PGltZyB3aWR0aD0yMiBoZWlnaHQ9MjEgc3JjPSJodHRwczovL3AxLnFpbmdndW8uY29tL0cxL00wMC8zRS9BQS9yQkFDSmxUSW1ZUERhU3hrQUFBQk9IVXJsaVExNjMucG5nIj4seDxpbWcgd2lkdGg9NDQgaGVpZ2h0PTIxIHNyYz0iaHR0cHM6Ly9wMi5xaW5nZ3VvLmNvbS9HMS9NMDAvM0UvRTkvckJBQ0oxVEltWVB5QTQ3REFBQUJtcklNVFN3NTUzLnBuZyI+PGJyPuKItHh5PGltZyB3aWR0aD01OSBoZWlnaHQ9MjEgc3JjPSJodHRwczovL3AxLnFpbmdndW8uY29tL0cxL00wMC83My8xRS9yQkFDRTFUSW1ZUFFrSjJSQUFBQjMwNHlXVFE3NTkucG5nIj48YnI+5omA5LulPGltZyB3aWR0aD0zOCBoZWlnaHQ9NDIgc3JjPSJodHRwczovL3AxLnFpbmdndW8uY29tL0cxL00wMC9BQS8yOC9yQkFDRkZUSW1ZT3hVUEhRQUFBQ1dYWTZVVjAxMjIucG5nIj48YnI+5pWF6YCJQw==
4/5单选题
难度：
4.
a、b、c是△ABC的三边，则
| A | -2C |
| B | -2b |
| C | a-b-c |
| D | a-b+c |
- 提示1：
- PHA+PGltZyBzcmM9Imh0dHBzOi8vcDIucWluZ2d1by5jb20vRzEvTTAwLzNFL0FBL3JCQUNKbFRJbVlDQy1kbWJBQUFCNldld0NBazYxOC5wbmciIGRhdGEtY2tlLXNhdmVkLXNyYz0iaHR0cHM6Ly9wMi5xaW5nZ3VvLmNvbS9HMS9NMDAvM0UvQUEvckJBQ0psVEltWUNDLWRtYkFBQUI2V2V3Q0FrNjE4LnBuZyIgaGVpZ2h0PSIyMSIgd2lkdGg9IjU5Ij7kuozmrKHmoLnlvI/nmoTpnZ7otJ/mgKc8L3A+
正确答案：QQ==
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
5/5单选题
难度：
5.
若
，则a与3的大小关系是（）
| A | a＜3 |
| B | a≤3 |
| C | a＞3 |
| D | a≥3 |
- 提示1：
- PHA+PGltZyBzcmM9Imh0dHBzOi8vcDIucWluZ2d1by5jb20vRzEvTTAwL0FBL0MxL3JCQUNGRlRKcWszenczNXpBQUFEYUY4dkozUTcxNi5wbmciIGRhdGEtY2tlLXNhdmVkLXNyYz0iaHR0cHM6Ly9wMi5xaW5nZ3VvLmNvbS9HMS9NMDAvQUEvQzEvckJBQ0ZGVEpxazN6dzM1ekFBQURhRjh2SjNRNzE2LnBuZyIgaGVpZ2h0PSI0MiIgd2lkdGg9IjIwNCI+5LqM5qyh5qC55byP55qE6Z2e6LSf5oCnPC9wPg==
正确答案：Qg==
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