焊接弯头的弯曲半径一般要求取（）倍的管子外径，热弯弯头弯曲半径一般取（）倍的管子外径。
参考答案：1-1.5；大于等于3.5
阅读小天地。
Hello, I am Wu Dong. I have a new classroom. It's nice and clean. The fan is green. The teacher's desk is
yellow. There are many desks and chairs. I like my classroom.
根据短文内容，判断下列句子的正(√)误(×)。
( ) 1. The classroom is clean.
( ) 2. The teacher's desk is blue.
( ) 3. The fan is green.
( ) 4. There are many desks and chairs in the classroom.
( ) 5. Wu Dong likes his classroom.
对于财政支出增长现象的解释，比较有影响的是（）。
A.皮考克和魏斯曼的“公共收入增长引致论”
B.瓦格纳的“政府活动扩张法则”
C.凯恩斯的“国家干预理论”
D.鲍莫尔的“非均衡增长模型”
E.马斯格雷夫和罗斯托的“经济发展阶段论”
