1B. This inequality is generally a multiple-choice question, and the minimum value is taken. It is particularly important that these three numbers are in the same position and can be rotated. Generally, the extreme value is taken when three numbers are equal, so x=y=z=2 is brought in to get 12.

2 b. The difference between this problem and the previous one is that C, A and B are equal and can be rotated, but C can't, but it is found that d=4c is used instead, a+b+d= 1, a+√b+d, and the maximum rotation of abd is equal, so,

A = B = D = 1/3, and c =112 is rounded up to get the root number 3.

3 The answer is at least 37,1+2+3+4+5+6+7+8+1+12+14+16+65438.

4 root number 3, the reason is the same as the second question.

5 b. This problem can give a=c= 16, b=2, and the D option can be excluded. Observing the three options of abC, we can see that the two numbers of ab can be rotated in the equation, or there is no difference in the status of AB, so the inherent mathematical relationship between the two options of AC is actually the same, that is, the right one is wrong together, so we exclude B together.

Conclusion: There is no need to solve the problem step by step. Flexible reasoning from options and experience will save a lot of time and leave room for big questions in the exam, but it is important to understand the internal reasons afterwards. To be honest, the step-by-step solution to these questions is not very good, but as the questions in the examination room, I think I can "solve" them as above.