Which of the following are homogeneous solutions salt water air sand and water vinegar cement

enhanced global partnerships and exploration capabilities may advance international preparedness for protecting the earth from catastrophic events such as some asteroid strikes, advancing collaborative research on space weather and protecting spacecraft by developing new means for space debris removal.

1. b.

2. d.

3. a.

5. d.

6. c.

these are the only ones that i know, i hope this , and good luck.