What do these two changes have in common?
mixing lettuce and salad dressing
sewing an apron

 - Both are caused by cooling.
 - Both are chemical changes.
 - Both are caused by heating.
 - Both are only physical changes.
Step 1: Think about each change.
Mixing lettuce and salad dressing is a physical change. Together, the salad and dressing make a mixture. But making this mixture does not form a different type of matter.
Sewing an apron is a physical change. The fabric and thread that make up the apron get a new shape, but the type of matter in each of them does not change.
Step 2: Look at each answer choice.
Both are only physical changes.
Both changes are physical changes. No new matter is created.
Both are chemical changes.
Both changes are physical changes. They are not chemical changes.
Both are caused by heating.
Neither change is caused by heating.
Both are caused by cooling.
Neither change is caused by cooling.