When you go outing with your sisters you must see to that they are safe.A. everythingB.

问题补充：

When you go outing with your sisters, you must see to that they are safe.

A. everything

B. it

C. them

D. yourself

答案：

A. everything

(答案→)B. it

C. them

D. yourself

解析：固定词组。固定词组see to it that…务必…；句意：当你和你妹妹们外出的时候，你务必要确定她们的安全。故B正确。