按发生机制，双吸气见于哪类呼吸困难
A．肺源性
B．心源性
C．中毒性
D．呼吸中枢性
E．精神性
参考答案：D
想一想，选一选。
( )1. It's warm today!
( )2. It's hot today.
( )3. It's cool today.
( )4. It's cold today.
A. Put on your T-shirt.
B. Put on your coat.
C. Take off your jacket !
D. Put on your sweater.
寄单索偿是指出口方指定银行向开证行寄送单据，随附面函向它（），或寄单给开证行向偿付行索偿。
