22. When you do exercises, your heart works better. It is able to______ more blood while beating more slowly.
A. produce
B. pump
C. increase
D. bump
(责任编辑:admin) |
22. When you do exercises, your heart works better. It is able to______ more blood while beating more slowly.
A. produce
B. pump
C. increase
D. bump
(责任编辑:admin) |