Question

to find out why getting enough sleep is important, researchers conduct sleep studies. the researchers learn a lot when they do these studies. for example, the studies have found that people who sleep too little have more problems with memory and bad moods. which phrase from the paragraph also means to conduct something? learn a lot do these studies sleep too little find out why

Explanation:

We analyze the context: the sentence says "researchers conduct sleep studies" which is followed by "when they do these studies". This shows "conduct sleep studies" matches "do these studies".

Answer:

○ do these studies