A. They are looking for the man and his dog which have lost the way in the forest.

B. They are looking for the man and his dog that have lost the way in the forest.

C. They are looking for the man and his dog who have lost the way in the forest.

D. They are looking for the man and his dog what have lost the way in the forest.

A.that

B. which

C. whom

D. who

A. I have some homework whom I must do tonight.

B. I have some homework which I must do tonight.

C. I have some homework in which I must do tonight.

D. I have some homework who I must do tonight.

A. I have seen several houses, most of that are quite unsuitable.

B. I have seen several houses most of which are quite unsuitable.

C. I have seen several houses, which are quite unsuitable.

D. I have seen several houses, most of which are quite unsuitable.

A. The street, which leads to my school, is bad and narrow.

B. The street which leads to my school is bad and narrow.

C. The street which is bad and narrow lead to my school.

D. The street which leading to my school is bad and narrow.

A. that

B. which

C. who

D. whose