Lt is on the desk just now.这句话的错误在哪里?

Lt is on the desk just now.这句话的错误在哪里? 句型转换改一般疑问句1.there are two cakes on the desk( ) ( )cakes are there on the desk?2.lt is a new lamp( )is it? lt's( )the desk. is ,under ,teacher's desk,lt,the连词成句 the book is on the desk. the lamp is on the desk. Whose is the bag on the desk? The book is on the desk. lt's in the desk. There is alarm clock on the desk. is there a book on the desk? is your book on the desk (陈述句) There is a lamp on the desk. （who)pencil is on the desk? is it on the desk改成陈述句 The box is on the desk.-----yes,the desk is ( )the box.A.ON B.UNDER. the desk on the computer is （.）the desk on the computer is （.） 连成句子 lt's on the floor,between the bookcase or the desk.(改错）