In what circumstances will the juvenile court grant a motion to prevent the District Attorney from presenting the evidence against appellant?

In the present case, the juvenile court expressly advised appellant of the Boykin rights, as we have set forth in the statement of facts. While the court did not use the phrase "confront your accusers," it did expressly advise appellant that the district attorney had to prove the case against appellant and that appellant's attorney would be permitted to "take on" the witnesses against appellant. The meaning of that phrasing is unmistakable and possibly conveys to a teenager the meaning of this right better than the more abstract phrase "confront" one's accusers. In any event, the advisements given by the juvenile court were sufficient, in light of all the circumstances of the hearing, to affirmatively show that appellant's admission of the petition was intelligently and voluntarily made. That is to say, nothing in the additional colloquy between the juvenile court and appellant gives any indication that appellant did not understand the rights he was giving up by admitting the petition. Accordingly, appellant has not established that his admission of the petition was invalid under the federal Constitution. (People v. Howard, supra, 1 Cal.4th at p. 1178.)