【单选题】Q345B(16Mn)钢焊条电弧焊时,可采用( )焊条。
【单选题】使用碱性焊条(如J506、J507)时,需在()温度下烘干1~2h。
【单选题】关于泵的下列说法中准确的是?
B.
泵的总效率是容积效率、水力效率、机械效率之和
C.
泵的允许吸上真空度和必需汽蚀余量都可由同样的汽蚀试验求出
【简答题】听对话,回答问题: 1. Whose keys did the man see? [ ] A. Julia's B. Dad's C. Linda's 2. Julia's keys are ______. [ ] A. under the table B. in her pocket C. on the table
【简答题】The keys are ________ the chair.( 在下面 ) 2. My English book is ___ the sofa.( 在上面 ) 3. - Where’s my baseball? - It’s______ the table. ( 在下面 ) 4. - Where’re your keys? - They’re______ the dresser. ( 在上面...
【单选题】耐候钢焊接使用碱性焊条(如J506、J507)时,需在350~400℃温度下烘干()。
【单选题】The keys near the bag.
【简答题】句型转换。 1. Is the book under the sofa? (做否定回答) ______, ______. 2. The keys are on the dresser . (对画线部分提问) ______ ______ the keys? 3. Is it in the backpack? (改为复数形式) ______ ______ in the backpack? 4. I k...
【单选题】J422、J506、J507、J502焊条直径5mm焊接电流()。
【简答题】仔细听,根据对话内容判断下列句子的正“T”误“F”。 ( )1. His keys are not on the sofa. ( )2. The ID car is on her desk. ( )3. The hat is on the bed. ( )4. His baseballs are in the pencil case. ( )5. The b...