心源性呼吸困难的主要原因是
A.肺循环瘀血B.体循环瘀血C.气道痉挛狭窄D.呼吸中枢兴奋E.极度紧张、恐慌
参考答案:A
句型转换。
1. There are some offices in our school. (改为否定句)
There ______ ______ offices in our school.
2. There is a bike in front of the car. (改为一般疑问句, 并作肯定回答)
______ ______ a bike in front of the car?
Yes, ______ ______ .
3. There are some dictionaries on the desk. ( 对划线部分提问)
______ ______ dictionaries ______ ______ on the desk?
海鲜与()大量同时食用,有可能导致严重食物中毒现象发生。
A.富含VC
B.富含VB
C.富含VA
D.富含VD