I believe it is oxygen and carbon dioxide
Answer:
refrain from using or disposing of (something); retain for future use.
Explanation:
There is a valve at the meeting point between each ureter and the bladder prevents the back flow of urine from the urinary bladder to the kidney
Gulls are most likely to be infected by this parasite :)
The answer is a. plant cells have cellulose and animal cells don't.
