市面上出售的大米中有些是富硒大米，其中含有人体需要的硒元素，它可以有效调节人体的免疫能力，增强人体防癌抗癌能力．我国也享有“世界硒都”的美誉．已知硒的原子结构示意图如图所示，则：

（1）硒原子的核电荷数为____ ，核外电子层数为____ ，最外层电子数为____ ，易形成____ （“阴”或“阳”）离子．

（2）与硫相似硒也能与氧气发生反应，请写出硒（Se）在氧气中燃烧的化学方程式为　____ ．

____ Since he fell off the bike, John _____________（stay） in bed for a week．
____ ——What is his plan after leaving school?——He _______________（go） to Beijing for education．
____ Could you please ________________（not speak） so loud?
____ David preferred __________（sell） newspapers to doing housework when he was young．
____ The teacher has finished ________________（interview） the parents．
____ You _________________（not laugh） at disabled people．It's impolite．
____ If I ________（be） you, I would help the homeless people．
____ You should say “Thank you” when you ________（give） something as a present by your friends．
____—— I called you yesterday night, but you were not at home．——I ____________（drive） home on the way at that time．
____ Young children should __________（allow） to choose their own clothes．