4.
- Another word for souvenir
5.
- A verb and two letters like "if"
6.
- Another word for concealed
7.
- Another word for without risk
8.
- Another word for within
9.
- We should take take of XXX environment
10.
- Mix blue and yellow to get ???
11.
- convert carbon dioxide, water, and sunlight into glucose and oxygen through photosynthesis.