无线电力负荷控制的电波信号主要依赖()传播。A.天波; B.地波; C.直射波; D

题型:单项选择题

问题:

无线电力负荷控制的电波信号主要依赖()传播。

A.天波;

B.地波;

C.直射波;

D.绕射波。

考点:电力负荷控制员电力负荷控制员技师电力负荷控制员技师题库
题型:单项选择题

Peter has many friends;_________can help him.

A.few of which

B.few of whom

C.few of that

D.few of them

题型:单项选择题

如图所示是太阳能LED照明路灯。它主要由太阳能电池板、LED灯头等部分构成。LED是一种发光二极管,通过电流能够发光,可以把电能直接转化成_________能。太阳能是_________能源(填“一次”或“二次”)、清洁无污染。

题型:单项选择题

对TAR的使用必须要谨慎,要对全网的组网有深入了解,一定要杜绝呼叫出现循环选路的可能性。()

题型:单项选择题

The "standard of living" of any country means the average person’s share of the goods and services which the country produces. A country’s standard of living, (1) , depends first and (2) on its capacity to produce wealth." Wealth" in this sense is not money, for we do not live on money (3) on things that money can buy. "Goods" such as food and clothing, and "services" such as transport and " (4) ". A country’s capacity to produce wealth depends upon many factors, most of (5) have an effect on one another. Wealth depends (6) a great extent upon a country’s natural resources. Some regions of the world are well supplied with coal and minerals, and have a fertile soil and a (7) climate; other regions possess none of them.

Next to natural resources (8) the ability to turn them to use. China is perhaps as well (9) as the USA in natural resources, but suffered for many years from civil and (10) wars, and (11) this and other reasons was (12) to develop her resources. (13) and stable political conditions, and (14) from foreign invasion, enable a country to develop its natural resources peacefully and steadily, and to produce more wealth than another country equally well (15) by nature but less well ordered.

A country’s standard of living does not only depend upon the wealth that is produced and consumed (16) its own borders, but also upon what is indirectly produced through international trade. (17) , Britain’s wealth in foodstuffs and other agricultural products would be much less if she had to depend only on (18) grown at home. Trade makes it possible for her surplus manufactured goods to be traded abroad for the agricultural products that would (19) be lacking. A country’s wealth is, therefore, much influenced by its manufacturing capacity, (20) that other countries can be found ready to accept its manufactures.

4()

A.recreation

B.enlightenment

C.refreshment

D.entertainment

题型:单项选择题

我国法定计量单位中压强的单位符号是()。

A.N

B.Pa

C.N.m

D.kgf/cm2

更多题库