埋弧焊时应注意选用容量恰当的______。A.弧焊电源 B.电源开关 C.熔断器 D

题型:多项选择题

问题:

埋弧焊时应注意选用容量恰当的______。

A.弧焊电源

B.电源开关

C.熔断器

D.送丝电动机

E.小车行走电动机

考点:焊工中级焊工焊工中级
题型:多项选择题

化简下列各题:

(1)3a2﹣9a+5﹣(﹣7a2+10a﹣5);

(2)﹣3a2b﹣(2ab2﹣a2b)﹣(2a2b+4ab2).

题型:多项选择题

(B)

The Hawaiian Islands are situated(位于) about two thousand miles away from North   America, right in the middle of the Pacific Ocean. Despite the distance the Islands actually make up the fiftieth state of the United States. The Islands were all formed by volcano(火山) eruption and on the largest of the islands, Hawai, or the Big Island, there are still two active volcanoes, the Mauna Loa and the Kilauea, which still erupt every few years.                                                                           

On the Hawaiian islands the natives have a particularly strange way of indicating(指明) directions. They don't use the north, south, east and west system common to the rest  of the world. They use the mauka and makai system. Mauka means "mountain".The mountains in Hawaii are always at the center of the islands, as these are volcanic is lands. Makai means "the sea". The islands are small and the system is simple. Wherever you want to visit, it can always be described in terms of where it lies in relation to the mountains and the sea. A typical conversation(谈话) between a native Hawaiian and a visitor might go as follows.                                                      

VISITOR: Excuse me! Could you tell me where the Sheraton Hotel is?            HAWAIIAN; Well ... Let me see ! From here it's two blocks mauka,and then one

block makai. You can't miss it!

1. This article would be most likely to appear in which of the following?     

A. A novel                          B. A collection of stories

C. A travel book                   D. a women's magazine

2. Choose the most suitable title for the article.

A. The Big Island                    B. Giving Directions in Hawaii

C. Volcanoes                        D. The Hawaiian Islands

3. In Hawaii the mountains are in the center of the islands because_____

A. of the weather                    B. of die geological conditions

C. the islands were created by volcanic eruptions

D. of the islands' location in the pacific

4. To find your way in Hawaii, you must _______.

A. refer to geographical directions      B. refer to well - known establishments

C. refer to the location of the mountains and the sea

D. refer to the earth and the sea

题型:多项选择题

表示某地6岁男孩体重的频数分布可用()。

A.圆图

B.复式条图

C.线图

D.直方图

E.构成比条图

题型:多项选择题

变压器引线与电缆连接时,电缆及其终端头均不得与变压器外壳()。

题型:多项选择题

出租汽车行政主管部门对于网约车经营申请作出行政许可决定的,应当明确经营范围、经营区域、经营期限等,并发放《网络预约出租汽车经营许可证》。

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