Firstly, schools should not ban mobile phones because some people may forget to bring their personal learning devices and it is more convenient to use their mobile phones.

Elaboration:

That is because, they could use their phones to do the classwork assigned or use the Student Learning Space work assigned from the teacher.

Secondly, students may also need to text or call their parents when there is an emergency or an important message.

Elaboration:

That is because their parents may be worried whether they are attending school or other admin family issues.

Thirdly, when students are studying in the library, they would also use mobile phones to listen to music.

Elaboration: Because they are indeed to use their phones to call their siblings

Elaboration:

HBL is effective in building independence and responsibility in students. When students undergo HBL, they are arranging their own studying pace and can learn in their preferred environment, taking charge of their own learning.

elaboration:

When students take charge of their own work and learn independently in HBL, they are more likely to put in the extra effort to make sure whatever they are learning will be retained in their memory. They can adjust their environment to whatever suits their liking and can learn at their own preferred pace which builds more passion and hard work towards the subject. For example, when I study at home for HBL, I make sure to consolidate what I have learnt throughout the day. When I am confused, I can replay the video or resource and learn at my own pace, which is not an option in school. In HBL, students will rise to the occasion and take charge of their own learning, doing whatever they can to learn and retain information, making learning effective.

Elaboration: For instance, some colour schemes used for uniforms even outside of school can include black. This may be perceived as chic and fashionable by the modern world but is associated greatly with death and deemed inauspicious by the hindu and chinese. Uniforms restrict people from following what they believe in and may cause discomfort to them by having to dress in a way they believe wrong. They act as barriers between students and their cultural beliefs. The westernised uniforms nowadays gets many disapproval looks from strong cultural believers, especially the older generation and even displeases the parents. Uniforms are biassed to fit in to only one culture. Students may also start disrespecting their own cultures as they may have forgotten the importance of their beliefs. This might stir some problems among the people. 

HBL is effective in allowing students to have a more flexible schedule in which they can spend more time on other things other than schoolwork.

elaboration:

During HBL, students are able to arrange their time and plan their day according to their own interest and preference. Instead of spending a fixed amount of time in their classrooms with fixed amount of time spent on each subject, they will be able to plan their own time to fit their learning preference. Other than that, students will also spend less travelling time since they will not have to travel to school. Travelling time can then be better spent on other things such as school work or their hobbies. This period of time is especially significant for students who live far from their schools and can be spent more wisely instead of wasting it on the public transport where they would most likely be on their phones. With no lessons in between, they are able to fit more tasks into their calendar. When students are able to be more frugal with their time, they can then have more free time after completing their school work, such as working on their interests and learning more about their hobbies, this keeps up their learning attitudes, making HBL effective. For example, I've been very interested in learning how to bake but have never had the opportunity to do so due to my busy schedule in school. However, on HBL days, I am able to allocate time to bake while also being able to finish my school work. Hence, during HBL, students will be given the opportunity to spend more time learning about knowledge that is not taught in the classroom, maintaining a good learning attitude among students and making HBL effective.