Complex sentence: It is generally believed that at 2 rpm or less, no adverse effects from the Coriolis forces will occur; at higher rates some people can become accustomed to it and some do not; but at rates above 7 rpm few if any can become accustomed.
Split into simpler sentences: It is generally believed that at 2 rpm or less, no adverse effects from the Coriolis forces will occur. At higher rates some people can become accustomed to it and some do not, but at rates above 7 rpm few if any can become accustomed.