A person’s nervous system will be affected if he doesn’t have enough amount of （）

A. Because it can make the beautiful evening scene.
B. Because it can bend the sun’s rays.
C. Because it can make it bright at dawn.
D. Because it can make the changes of different weather phenomena.

A. Thousands of children in America joined the investment clubs.
B. The children in investment clubs spend their Sunday studying their financial strategies.
C. There’re investment clubs throughout America.
D. In America, not only adults but also children join investment clubs.