________ a mobile phone can you ring ________ you want to talk with anywhere.

No student go out of school for snacks during the break without the teacher’s permission.

Someone who lacks staying power and perseverance is unlikely to ___ a good researcher.[ ]

Most of us see a doctor ______ when we get a cold or somethingThis won’t cost us a lot

Just be _______, you can’t make such great progress in a day. It takes time.