句子配对。
①How heavy is Tom?____ A. There are 15.
②How old is he?____B. He is 15years old.
③How much is the robot?____C. He weighs 51kg.
④How many boys are there under the tree?____D. It's September 15th.
⑤When is your birthday?____E. It's ¥15.
下列各项中,没有语病的一项是( )
已知命题p:∃x∈R,x>sinx,则p的否定形式为( )
15世纪中期到17世纪中期被西方史学家称为“扩张的时代”,主要原因是