What a shame that there are so many people there, but ______ dare stop the crime(违法、犯罪行为).

Maria is my father’s sister . So I call her ____ .

She sings very well. She can _______ the school music festival.

She is new here，so she has _______friends at school. 

Can the scientist ______ [iks'plein] the reasons for changing the plan?