给出下列命题：

①原命题为真，它的否命题为假；

②原命题为真，它的逆命题不一定为真；

③一个命题的逆命题为真，它的否命题一定为真；

④一个命题的逆否命题为真，它的否命题一定为真；

⑤“若m>1，则mx²－2(m＋1)x＋m＋3>0的解集为R”的逆命题．

其中真命题的个数是(　 　)

A．1

B．2

C．3

D．4

短文填空。

     Mr. and Mrs. Green (1) h______ a big house. Their house (2) h______ a kitchen (厨房), four bedrooms

and three other rooms. There are some trees (3) n______ to their house.

     They (4) h______ two cars. One is for Mr. Green and the other is for Mrs. Green. They (5) h______ two

children. One is a (6) s______, and the other (另一个) is a (7) d______. The children like (8) s______ very

much. The son has five (9) b______, nine (10) s______ balls and many baseballs. He likes playing (11) b______

every day. The daughter has eight (12) v______ balls, ten ping-pang balls (13) a______ seven (14) t______

balls. She plays (15) t______ ball every day.