Фото: Shatokhina Natalia / Globallookpress.com
Medium difficulty hints, answers for Feb. 27 PipsNumber (4): Everything in this space must add up to 4. The answer is 2-1, placed horizontally; 2-2, placed vertically.，这一点在Line官方版本下载中也有详细论述
Екатерина Графская (Редактор отдела «Наука и техника»)，详情可参考91视频
Optimization: Normalized IR → Normalized IR