膝胸或俯卧位可使呕吐减轻，常见于下列哪种情况（）。
A.幽门梗阻
B.十二指肠淤滞
C.消化性溃疡
D.早孕
E.胃肠神经症
参考答案：B
按括号内的要求改写下列各句。
1. Tom thinks they are scary. (改为否定句)
Tom _____ _____ they _____ scary. .
2. Her cousin likes thrillers. (就划线部分提问)
_____ _____ of _____ does her cousin like?
3. I want to see a movie. (改为同义句)
I want _____ _____ _____ a movie.
4. My favorite movie star is Jack Chan. (就划线部分提问)
_____ _____ your favorite movie star?
5. I like movies and I like Beijing Opera. (改为简单句)
I like movies _____ _____ _____.
6. She doesn't like to see movies. (改为肯定句).
She _____ _____ movies.
易患性、阈值的概念是什么二者有什么关系
