油罐用蒸汽吹罐前,必须先打开(),防止吹罐时温度高把油罐胀坏变形。
A、呼吸阀
B、人孔
C、检尺孔
D、透光孔
参考答案:B, C, D
读答句,写问句。
1. A:____________________________?
B: I am drawing pictures.
2. A:___________________________?
B: I often play football on weekends.
3. A:____________________________?
B: I have Chinese class at 9:50.
4. A:____________________________?
B: My favourite month is July.
5. A:____________________________?
B: My mother's birthday is in March.
关于妊娠诊断正确的是().
A.黑加征是宫体呈球形,宫颈着色
B.停经是确诊妊娠的症状
C.体内HCG高峰在停经40~50天
D.黑加征是确诊妊娠的征象
E.体内HCG高峰在妊娠8~10周