【简答题】电梯由一个起重间与一个配重组成。它们分别系在一根绕过定滑轮的钢缆的两端,如图所示。起重间(包括负载)的质量M=1200kg,配重的质量m=1000kg。此电梯由和定滑轮同轴的电动机所驱动。假定起重间由低层从静止开始加速上升,加速度a=1.5m/s 2 。试求:
【简答题】超级链接使访问者方便地从一个()转移到另一个网页。
【简答题】按相数不同,变压器可以分为 变压器、 变压器和 变压器。
【单选题】When you choose a freezer, remember it's probably going to be with you for a long time. No single style. or size is best, so it's important to know which freezer is right for your needs. First, decide...
A.
An upright model takes less room on the ground.
B.
An upright freezer is easier for people to put in and take out food.
C.
A chest freezer is more effective than an upright one.
D.
A chest model need manual defrost while an upright one needn't.
【单选题】听力原文: When you choose a freezer, remember it's probably going to be with you for a long time. No single style. or size is best, so it's important to know which freezer is right for your needs. First, ...
A.
Advantages and disadvantages of freezers.
B.
The best energy-efficient freezer.
C.
Defrosting a manual defrost freezer.
D.
Choosing and caring for a freezer.
【多选题】根据白金热线在壳体内安装的部位不同,热线式空气流量计可分为
【简答题】新视野视听说 Book 3 Unit 3 Page 39 (1)
【简答题】变压器种类很多,按相数分,可分为单相变压器和 变压器;按冷却方式分,可分为 变压器、 变压器、自冷式变压器和干式变压器。
【单选题】要对某种药物或治疗方法的效果进行检验和评价,常采用