What is pretty much settled according to Paul Sereno?

• A、Half of the dinosaurs lived alone. 

• B、Most dinosaurs moved long distances

• C、Many dinosaurs settled in the north. 

• D、Some dinosaurs lived in big groups.

56 （）

Henry will not be able to attend the meeting tonight because__________

• A、he must to teach a class

• B、he will be teaching a class

• C、he will teach a class

• D、he will have teaching a class