You may have encountered keyboards with an optional lift at the back of the board, raising the top keys higher than the space bar. Every set of hands is different, but for most people, pulling the backs of the hands towards the forearms increases strain. Negative tilt has the opposite effect by sloping in the other direction, lowering the top number keys while raising the edge with the spacebar. Many Alice and some split keyboards offer an optional negative tilt. I found it was more comfortable to enable that feature when I’m standing, and I preferred to have the keys flat when sat at my desk.
Photograph: Julian Chokkattu
，这一点在51吃瓜中也有详细论述
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在邹露璐看来，代孕引发的一系列民事法律难题之外，当下更亟待解决的，还是代孕子女的落户这一基础民生问题。“相较于抚养权归属的争议，孩子的身份确认、户口登记，是保障其生存权、发展权的首要前提。”她说。
This one was a lot better than others. For every SAT problem with 10 variables and 200 clauses it was able to find a valid satisfying assignment. Therefore, I pushed it to test with 14 variables and 100 clauses, and it got half correct among 4 instances (See files with prefix formula14_ in here). Half correct sounds like a decent performance, but it is equivalent to random guessing.