依照我国《民法通则》规定,被撤消的民事行为被认为是()。
A.从行为开始时无效
B.从行为人请求撤消时无效
C.从行为撤消时无效
D.从判决生效时无效
参考答案:A
The group of research workers are said to ________ to the dangerous nuclear radiation while they carried out their rescue task.
A.be exposed
B.have been exposed
C.exposed
D.be exposing
心理平衡是指导游员的精神始终保持愉快、饱满,在游客面前显示出良好的精神状态。( )