1.The scientist wrote down ------ series of things to do wit

1.The scientist wrote down ______ series of things to do with ______ nature ,such as a blue sky.
A.a;\ B.a;the C.\;\ D.\;the
2._______ about my mother's health,I went to my hometown last Sunday.
A.Concerning B.Concernde C.To be concerned D.Being concerned
3.There was a time ______ I lived in a smell village.
A.which B.that C.when D.where