受热面上的结渣积灰按不同区域分为哪几种形式?
参考答案:
按不同区域可分为镕渣、高温黏结灰、松灰和低温黏结灰等不同形式。
判断下列句子是否与短文相符,相符的写“T”,不相符的写“F”。
Buying Tickets (票)
Sam is a little boy, and he is only eight years old. One day he goes to the cinema. It is the first time for him
to do that. He buys a ticket and then goes in. But after two or three minutes he comes out, buys a second ticket
and goes in again. After a few minutes he comes out again and buys a third ticket. Two or three minutes later he
asks for another ticket.
Then the girl in the ticket office asks him, "Why do you buy so many tickets? How many friends do you
meet? " Sam answers, "No, I have no friend here. But a big boy always stops me at the door and tears my
tickets in piece. "
( )1. Sam is eight years old.
( )2. It is the third time for Sam to go to the cinema.
( )3. Sam bought two tickets.
( )4. Sam has no friend in the cinema.
发动机的缸体曲轴箱组包括汽缸体、下曲轴箱、()、汽缸盖和汽缸垫等。
A、上曲轴箱
B、活塞
C、连杆
D、曲轴