If you have a distension of the stomach that can mean one 4 or more things. you ate something bad or old. you spun around in circles and feel like throwing up. you get a headache and you feel sick from your stomach. you got a stomachache
Answer:
The correct answer is - they are both systems that are performing similar functions.
Explanation:
In the given question there are two different entities that do a similar kind of work or perform similar functions, however, the systems are different as one system involves the manpower of a worker whereas the other system involves the high power of a bulldozer.
The work is similar but the amount of the work varies as manual work done by a worker is less in comparison to the bulldozer.
You can easily remember it because the scientific name of leech is Hirudinaria. So it secretes anticoagulant named hirudin. Which help it to feed blood longer