张家口坝上与坝下过渡地带是()。
A.张北县
B.赤城县
C.宣化县
D.崇礼县
参考答案:B, D
The government has had to _______ with the opposition party on the new regulation, which will come to effect next month.
A.negotiate
B.bargain
C.connect
D.associate
下列换热器中,总传热系数量大的是()。
A、列管式换热器
B、套管式换热器
C、板式换热器
D、蛇管换热器