---- Who is it that is making so much noise upstairs?

---- ______ the students preparing for the New Year’s Party.

A．There are

B．They are

C．It is

D．That is

幼儿园儿童

A．适宜选用氟化钠牙膏
B．适合选用单氟磷酸的牙膏
C．可以与成人一样使用市售一般含氟牙膏
D．每次使用牙膏的用量要小
E．适宜选用氟化亚锡牙膏