Let() begin() class.A.us,us B.us,our C.we,our

Let() begin() class.A.us,us B.us,our C.we,our let us begin our class 是什么意思 （ ） everyone is here ,let us begin our class.A .Since B .For E( )is here.let us begin our class. ______everyone is here,let us begin our class we doing ( ) homework a.we b.us c.our Mr smith teaches _____English A.we B.us C.our Mr wang teaches ___English A.us B.our C.we This is ______room.A.we B.us C.our Mr smith teaches _____English.A.we B.us C.our, 选择填空一题Please ___ in class,boys and girls.Let us begin our cl Let us begin to have our class可以不加to吗?为什么