按照合同约定或者法律规定,在当事人之间产生特定权利和义务关系的是()
A.债
B.所有权
C.知识产权
D.担保物权
参考答案:A
解析:参见教材P22
The road is covered with snow.I Can’t understand _______ they insist on going by motorbike.
A.why
B.whether
C.when
D.how
坐公交车出行属于绿色消费行为之一。