1.Every student should do...<br/>their best<br/>her best<br/>his or her best <br/><br/>2.Neither of the girls... <br/>is able to babysit<br/>are able to babysit <br/><br/>3.Here...<br/>is the tickets for the game<br/>are the tickets for the game <br/><br/>4.Somebody left...<br/>their cell phone <br/>his cell phone<br/>his or her cell phone <br/><br/>5.<br/>Each of the teammates<br/>is contributing $5 for the gift<br/>are contributing $5 for the gift