You hurt others maliciously, teacher. Low-level? How did those students repair the maintenance parts? Let students give gifts? How funny! There's nothing. Tuition is your personal judgment. Prices are high or low, depending on the effect and your feelings. I don't mean to whitewash or discredit. Walker is more reliable. I learned from scratch, and the course is very tight. I am slow to absorb, and I have studied for two cycles. I got a job after I came out. Maintenance methods depend on your own understanding and efforts, and maintenance experience depends on your own summary, attention and accumulation. Nothing can be done overnight! Recommend Walker, don't believe you will know!