螺栓扣主要用在张紧和松驰拉索、缆风绳等，其使用时应钩口（）。
A.向里
B.向外
C.向下
D.向上
参考答案：C
His new novel is ________his own experience when he was studying in Harvard University.
A．based in
B．basing in
C．basing on
D．based on
一早产儿(胎龄35周)，出生时有窒息史，生后12h开始人工喂养。于生后第7天精神萎，胃纳减退，恶心、呕吐2次，腹胀，大便略稀，隐血试验阳性；腹部平片符合坏死性小肠结肠炎。下列X线表现除哪一项外均意味着病变严重
A．肠壁囊样积气
B．门静脉充气征
C．选择性肠袢扩张固定
D．腹腔渗液
E．气腹
