下列两个二糖a和b,其中______是还原性二糖;a的连接方式是______糖苷键;b的连接方式是______糖苷键。
参考答案:a;1,4’-α;1,2’-α,β-
She couldn't help _______when she saw her mother.[ ]
A. to cry
B. crying
C. cry
D. to crying
左心衰发展至全心衰时不出现()
A.呼吸困难加重
B.下肢水肿
C.呼吸困难减轻
D.咳嗽减轻
E.乏力、疲倦加重