根据题意得:x-2≥0,
解得:x≥2.
故选B.
Sun Tao has had a _______ English course, but he still doesn't know
A.six-month; how to spell this word
B.six months; how spell the word
C.six-months; how he should spell this word
D.six-month; how should he spell the word
有关心房颤动的治疗原则,下列不正确的是()。
A.治疗原发的心血管病
B.48小时内新发生者,应尽快复律,无需抗凝
C.经转复及维持治疗均无效,房颤持续时间一年以上者,治疗目的为控制心室率,预防心力衰竭
D.对房颤持续时间超过48小时者应在有效抗凝治疗后再复律
E.对合并心功能不全的心房颤动患者,应首选普罗帕酮控制心室率,防止心功能进一步恶化