3-7 days. According to the brief introduction of Ruisi education institution, the word shorthand course of Ruisi education takes 3-7 days. A course to help children memorize test vocabulary efficiently. The shorthand course relies on AI electronic teaching aid and teaching aid, and uses the four technical principles of hippocampus LTP technology, short-term memory anti-attenuation model, anti-memory fatigue and excitement guidance, and memory reinforcement to build memory, so that children can form oral muscle memory after learning, which fundamentally solves the problem of word forgetting caused by students' memorization and reading, and helps children improve their English scores quickly.