锅炉在开始排污时,首先要()一次阀,然后再慢慢打开二次阀进行排污,在结束排污时,先把二次阀关闭,随后再()一次阀。
参考答案:打开;关闭
回答问题。
1. When do you usually get up in the morning?
_________________________________.
2. What's your favourite class at school?
3. What do you usually do on the weekend?
4. What's your favourite season in a year?
5. What do you usually do in that season?
6. When do you go to bed?
最可能的诊断是
A.尖锐湿疣B.结核C.硬下疳D.淋病E.外阴癌