为了防止佝偻病的发生，促进少年儿童骨髓的发育，除了补充含钙的无机盐外，还应注意补充（　　）

A．维生素A

B．维生素B

C．维生素C

D．维生素

—Why did Miss Wang look so worried when we saw her?

—Because she wondered       .

A．where did the other students go

B．when would the policeman come

C．if her students had survived the earthquake

D．what she will do during the trip