皮皮学，免费搜题
登录
搜题
【单选题】
消化道恶性肿瘤,钡剂检查时看不到下列哪项征象?A.
腔内不规则龛影
B.
黏膜破坏、消失
C.
腔内不规则充盈缺损
D.
项圈征
E.
僵硬、蠕动消失
手机使用
分享
复制链接
新浪微博
分享QQ
微信扫一扫
反馈参考答案：
举一反三
【单选题】关于蛋白质二级结构α-螺旋的叙述正确的是
A.
天然的蛋白质都是右手α-螺旋
B.
多聚Lys和多聚Ile因为空间位阻效应而不能形成α-螺旋
C.
维持α-螺旋的作用力主要是肽键
D.
α-螺旋中，每个氨基酸残基的羰基氧与前面第四个氨基酸残基的亚氨基氢形成氢键
【单选题】下列有关蛋白质α-螺旋的叙述，正确的是( )。
A.
属于蛋白质的三级结构
B.
由二硫键构成，起稳定作用
C.
由盐键构成，起稳定作用
D.
多为右手螺旋，3．6个氨基酸残基升高一圈
【单选题】An argue of the software firms for the security problems is that
A.
software's performance depends on many factors.
B.
information is stolen by hackers.
C.
there is no law to control the software industry.
D.
software's quality decreases by the threat of sweat.
【简答题】A．It's a strange thing. B．Someone has come to see me. C．I feel very surprised at the news. D．There was an accident on the road.
【单选题】A firewall is a (1) ystem designed to (2) n organization's network against threats.
A.
operating
B.
programming
C.
security
D.
service
【单选题】It's one thing... but something else entirely if it winds up on your dinner plate.
A.
appears in the end
B.
annoys
C.
blows away
D.
moves upwards
【简答题】Time to Dance Are you the kind of person who likes to move with music? It's a natural thing to do. Even little children start jumping up and down when they hear music. Scientists say that animals danc...
【单选题】Will Quality Eat up the U.S. Lead in Software? If U. S. software companies don't pay more attention to quality．they could kiss their business good-bye. Both India and Brazil are developing a world-cla...
A.
Germany.
B.
The U．S.
C.
Brazil
D.
India
相关题目：
参考解析：
知识点：
题目纠错 0
发布
