People who do not work hard and have poor self-discipline may play mobile phones in the class, listen to the online class casually, and do not practice after listening.
Do not try to self-discipline poor people may play in class mobile phone, net class casually listen to, listen to do not practice, may be half-way to waste, poor effect.
People who don't work hard and have poor self-discipline may play with mobile phones in class, listen to online classes casually, do not practice after listening, may give up halfway, with poor effect.