找出句中错误并改正。

(    )1.  Would you like playing the guitar?            

               A             B      C      D

(    )2. Let's go or play the piano.____        

             A        B   C    D

(    )3.  -What do you like? -I'd like monkeys.            

                A        B                  C          D

(    )4.  I like playing the accordion.  Would you like it, too?

              A       B                                 C                 D

(    )5. -Can I help you? -I’d like a trouser.____

                  A          B          C          D

(    )6.  -How many is it？-It's five yuan.       

                        A       B      C          D

简述RS-232C的电气特性。