单项选择题

Dr. Goldspink disagrees with the proposal that oestrogen could protect heart because _________.

A．female sex hormone can increase blood flow
B．female sex hormone can be beneficial to blood vessels
C．female heart function hardly drops when oestrogen levels fall greatly
D．female heart function improves though not obviously
<上一题 目录 下一题>
热门 试题

单项选择题
The power of the female heart remains undiminished between the ages of 18 and 70 probably because _________.
A．women almost lose no contractile muscle cells in the walls of their hearts
B．women's oestrogen has a protective effect on their heart
C．the size of their heart chambers is different from men's
D．the thickness of the female heart's muscular wall is different from men's
单项选择题
Two recent papers in Science magazine claim to have found evidence which contradicts the traditional notion that _________.
A．relatively harsh environments are the nurseries of evolution
B．evolution occurred in regions with biological diversity
C．new forms of life come into being in near-shore areas
D．species of birch and redwood originated in the south
相关试题