1/3单选题
难度：
1.设
，b=
,则（）
，b=,则（） | A | a |
| B | a |
| C |  |
| D |  |
正确答案：QQ==
6Kej77yaPGltZyB3aWR0aD05OSBoZWlnaHQ9MjEgc3JjPSJodHRwczovL3AxLnFpbmdndW8uY29tL0cxL00wMC8yRS9FRS9yQkFDSjFTaDliN1JkVjk4QUFBQ1VrV2xDaEE1MjEucG5nIj4sPGltZyB3aWR0aD0xNTMgaGVpZ2h0PTQyIHNyYz0iaHR0cHM6Ly9wMi5xaW5nZ3VvLmNvbS9HMS9NMDAvNjIvQjAvckJBQ0UxU2g5YjdCTWxpbkFBQUMtU3JTNGxzNjE2LnBuZyI+LDxpbWcgd2lkdGg9MTUzIGhlaWdodD00MiBzcmM9Imh0dHBzOi8vcDIucWluZ2d1by5jb20vRzEvTTAwLzhGLzZDL3JCQUNGRlNoOWI3eEtaNmhBQUFDLVJWWDVlbzA1OC5wbmciPizmiJHku6zlj5HnjrA8aW1nIHdpZHRoPTI4IGhlaWdodD0yMSBzcmM9Imh0dHBzOi8vcDIucWluZ2d1by5jb20vRzEvTTAwLzJFL0IwL3JCQUNKbFNoOWI2RDNabzJBQUFCUzJNR2RyZzgyOC5wbmciPumDveWkp+S6jjDlsI/kuo4x77yM6K6pYuWSjGPlgZrllYbvvIzmr5TovoNi5ZKMY+eahOWkp+Wwj++8jDxpbWcgd2lkdGg9NzEgaGVpZ2h0PTYyIHNyYz0iaHR0cHM6Ly9wMS5xaW5nZ3VvLmNvbS9HMS9NMDAvMkUvRUUvckJBQ0oxU2g5YjZ3b0QwSUFBQUMtTHpFQVE4MzI3LnBuZyI+PTxpbWcgd2lkdGg9ODEgaGVpZ2h0PTIxIHNyYz0iaHR0cHM6Ly9wMS5xaW5nZ3VvLmNvbS9HMS9NMDAvNjIvQjAvckJBQ0UxU2g5Yjd4RDlFeUFBQUNUWjRfbHFJNzQwLnBuZyI+LOaJgOS7pTxpbWcgd2lkdGg9MzcgaGVpZ2h0PTIxIHNyYz0iaHR0cHM6Ly9wMS5xaW5nZ3VvLmNvbS9HMS9NMDAvMkUvQjAvckJBQ0psU2g5YjdBNTJaLUFBQUJVYjFWVnZvNjU2LnBuZyI+ITxicj7miYDku6XmraPnoa7pgInpobnmmK9BIQ==
，b=
,则（） 
，b=
,则（）