神经纤维中相邻两个锋电位的时间间隔至少应大于______
As heart disease continues to be the number-one killer in the United States, researchers have become increasingly interested in identifying the potential risk factors that trigger heart attacks. ( Passage Two)
(In) his (latest) article, the reporter criticized the way (which) the racial problem was (being handled).
然而，在那个国家还有成千上万的年轻人却很难找到工作。
We ______ having picnic for so long time.
某校在校外教育中，班主任要求本班学生必须参加一项小组活动。这不符合校外教育特点中的______
She hurried back to school 怕缺课太多.
组织液的生成主要取决于______
A.脐水平以上静脉血流向上，脐以下血流向下B.脐水平以上静脉血流向下，脐以下血流向上C.腹壁静脉血流全部向上D.腹壁静脉血流全部向下E.以脐为中心血流向四周
When Jack arrived he learned Mary ______ for almost an hour.
书面要约生效的时间是______
人类掠夺式的开发造成生态环境破坏是生物灭绝和濒危的主要原因。
Jack was in the conference room (discussing) plans with (the other) committee members when the chairman (had called) to say (he'd be late).
We love peace, yet we are aot the kind of people to yield ______ any military threat.
(A number) of these (who) (study) engineering is improving (steadily).