下列选项叙述错误的是（　　）

A．命题“若x≠l，则x²-3x十2≠0”的逆否命题是“若x²-3x十2=0，则x=1”

B．若p∨q为真命题，则p，q均为真命题

C．若命题p：∀x∈R，x²+x十1≠0，则¬p：∃x∈R，x²+x十1=0

D．“x＞2”是“x²一3x+2＞0’，的充分不必要条件

For the sake of enough time for study and rest, students are _____ from using cellphones in our school.

A．encourged

B．forbidden

C．required

D．kept