【单选题】有关胚胎期造血器官的叙述中,正确的是
A.
卵黄囊壁上的血岛是最初的造血中心,它起源于外胚层细胞
C.
脾脏在第3个月时,开始产粒细胞,以后产生红细胞
E.
骨髓是产生红细胞、粒细胞、巨核细胞和单核细胞的场所,不产生淋巴细胞
【单选题】以产品的等级来衡量某种产品的质量好坏,则该产品的等级是()
【单选题】听力原文:M: I thought that you were going to the convention in Atlanta last Saturday. You said it many times before. W: I was planning to, but I haven't been feeling well, so I stayed at home and did noth...
B.
At a convention centre.
【单选题】以产品的等级来衡量某种产品质量的好坏,则该产品的等级是()
【多选题】第五章19.公民的权利义务相一致,旅游者在享有权利的同时也应当履行义务。旅游者的义务主要包括()
【单选题】听力原文:Q: Didn't I meet you at the convention a couple of years back? (A) I'm looking forward to meeting you. (B) Yes, you were wearing glasses then. (C) Yes, it will be held at the Granprix Hotel. (5)
【简答题】胚胎时期最初的造血器官是_________,24周前主要造血器官是_________,24周后至出生后主要造血器官为_________。
【单选题】严重创伤的最佳抢救时间是受伤之内的()分钟
【多选题】第五章19.公民的权利义务相一致,旅游者在享有权利的同时也应当履行义务。旅游者的义务主要包括()
【单选题】听力原文:M: I thought that you were going to the convention in Atlanta last Saturday. You said it many times before. W: I was planning to, but I haven't been feeling well, so I stayed at home and did noth...
B.
She went to a convention.
C.
She went to a hospital.