烯烃的性质比()的性质活泼。
A、烷烃
B、炔烃
C、二烯烃
D、环烃
参考答案:A
Is this the hotel _____ you said we were to stay in your letter?
A.where
B.which
C.in that
D.in which
( )是导游服务规避风险的必要手段。
A.导游职业自由化
B.导游服务商品化
C.导游服务规范化、标准化
D.导游手段高科技化