PER CURIAM.

In Leandro v. State, 346 N.C. 336, 488 S.E.2d 249 (1997) and Hoke County Board of Education v. State, 358 N.C. 605, 599 S.E.2d 365 (2004),2 this Court first found and then reaffirmed that the Constitution of North Carolina guarantees "every child of this state an opportunity to receive a sound basic education in our public schools." 346 N.C. at 347, 488 S.E.2d at 255; accord 358 N.C. at 649, 599 S.E.2d at 397. Following our opinion in Leandro, the State created a prekindergarten program (formerly "More at Four") for at-risk four-year-old children. Plaintiffs brought the instant proceeding to challenge changes to this program made by the General Assembly in 2011. We conclude that subsequent legislation enacted in 2012 rendered this controversy moot.

The instant proceeding arose after the General Assembly instituted changes to North Carolina's prekindergarten program in the 2011 biennial budget law. See Current Operations and Capital Improvements Appropriations Act of 2011, ch. 145, sec. 10.7, 2011 N.C. Sess. Laws 253, 354-56. Plaintiffs filed a "Motion for Hearing on Curtailment of Pre-Kindergarten Services for At-Risk Children, Elimination of EOC Testing, and Defendants' Compliance with North Carolina's Constitutional Requirements," in essence seeking a judicial determination that the 2011 legislative changes failed to comply with the State's constitutional obligations recognized in Leandro and Hoke County. After a hearing, the trial court on 18 July 2011 entered a "Memorandum of Decision and Order re: Pre-Kindergarten Services for At-Risk Four Year Olds" (the "order"), finding that some of the changes violated the Constitution of North Carolina and mandating that the State "not deny any eligible at-risk four year old admission to the North Carolina Pre-Kindergarten Program."

In its order, the trial court faulted two of the changes made by the General Assembly to the prekindergarten program, finding that subsection 10.7(f), which purportedly capped the percentage of "at-risk" children permitted in the prekindergarten program, and subsection 10.7(h), which instituted a co-payment requirement for certain students enrolled in the program, were unconstitutional. The State appealed the trial court's order to the Court of Appeals. However, approximately one year after the trial court issued its order and while the appeal was pending, the General Assembly amended the challenged statutory provisions. See Act of June 5, 2012, ch. 13, sec. 2, 2011 N.C. Sess. Laws 65, 65-66 (Reg.Sess.2012). These amendments substantially altered the language of subsection 10.7(f) and repealed subsection 10.7(h). Id. Thereafter, the Court of Appeals affirmed the trial court in part and dismissed the appeal in part. Hoke Cnty. Bd. of Educ. v. State, ___ N.C.App. ___, 731 S.E.2d 691 (2012). This Court allowed the State's Petition for Discretionary Review.

We now consider whether this appeal is moot as a result of these most recent amendments. "Whenever, during the course of litigation it develops that ... the questions originally in controversy between the parties are no longer at issue, the case should be dismissed, for courts will not entertain or proceed with a cause merely to determine abstract propositions of law." In re Peoples, 296 N.C. 109, 147, 250 S.E.2d 890, 912 (1978) (citations omitted), cert. denied, 442 U.S. 929, 99 S.Ct. 2859, 61 L.Ed.2d 297 (1979). This Court consistently has "refused to consider an appeal raising grave questions of constitutional law where, pending the appeal to it, the cause of action had been destroyed so that the questions had become moot." Benvenue PTA v. Nash Cnty. Bd. of Educ., 275 N.C. 675, 680, 170 S.E.2d 473, 477 (1969) (citing Wikel v. Bd. of Comm'rs of Jackson Cnty., 120 N.C. 311, 120 N.C. 451, 27 S.E. 117 (1897)). When, as here, the General Assembly revises a statute in a "material and substantial" manner, with the intent "to get rid of a law of dubious constitutionality," the question of the act's constitutionality becomes moot. State v. McCluney, 280 N.C. 404, 405-07, 185 S.E.2d 870, 871-72 (1972) (action challenging state obscenity statute under United States Supreme Court precedent held moot after General Assembly repealed and replaced statute). "The court takes judicial notice [of intervening legislation] without formal supplemental plea...." Wikel, 120 N.C. at 312, 120 N.C. at 452, 27 S.E. at 117. Once the issues on appeal become moot, the appropriate disposition is to dismiss the appeal ex mero motu and to vacate the decision of the Court of Appeals. See, e.g., Messer v. Town of Chapel Hill, 346 N.C. 259, 261, 485 S.E.2d 269, 270 (1997) (per curiam) (citing State ex rel. Utils. Comm'n v. S. Bell Tel. & Tel. Co., 289 N.C. 286, 290, 221 S.E.2d 322, 324-25 (1976)).

The 2012 amendments enacted by the General Assembly in the wake of the trial court's order are readily comparable to the intervening legislation in McCluney. The repeal of subsection 10.7(h) and the alteration of subsection 10.7(f) constitute "material and substantial" changes to the provisions that the trial court found unconstitutional. See McCluney, 280 N.C. at 405, 185 S.E.2d at 871. Accordingly, we conclude that the questions originally in controversy between the parties are no longer at issue and that this appeal is moot. We express no opinion on the legislation now in effect because questions of its constitutionality are not before us. Id. at 407, 185 S.E.2d at 872. Our mandates in Leandro and Hoke County remain in full force and effect.

We dismiss this appeal as moot ex mero motu and vacate the opinion of the Court of Appeals. This case is remanded to the Court of Appeals with instructions to vacate the 18 July 2011 order of Superior Court, Wake County.

APPEAL DISMISSED AS MOOT; COURT OF APPEALS OPINION VACATED; AND REMANDED.