This kind of fish is r____ in oil, which is good for people who have heart trouble.
-- they have a basketball?
-- No, they don’t have .
如图a是“研究影响滑动摩擦力大小的因素”实验.
如图所示人体部分生理活动,请据图回答下列问题:
下列句中划线的词语,解释正确的一项是( )