Can someone please help me​

The low and midlevel clouds that look like cotton balls are

Explain how stock market speculation contributed to the great depression.

The picture below shows president richard nixon and the first lady standing before the great wall of china in 1972. they are smiling - as are the chinese with them. when this picture was shown on american television, americans were aware that it was a historic moment. what are two reasons why this moment was important for both china and the united states?