在线路长度无明显变化的情况下,单次光缆割接前后每个光放段线路衰耗增加应小()dB。A

题型:单项选择题

问题:

在线路长度无明显变化的情况下,单次光缆割接前后每个光放段线路衰耗增加应小()dB。

A、0.2

B、0.5

C、0.8

D、1

考点:传输线路维护人员考试传输线路维护人员考试题库
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一件上衣的售价是480元,比原价降低了20%,降价了多少元?

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Complete the dialogue with proper words or sentences.

A: Good morning, madam!

B: Good morning, sir!

A: You look worried. 1._____________?

B: My son got lost when I was talking with my friend in the park. I've looked

    for him everywhere, but I can't find him. What shall I do?

A: 2._____________. Tell us something about him, and we can help you.

B: Thank you, sir.

A: Now please tell me 3._____________.

B: He's six years old.

A: 4._____________?

B: He's thin and tall with big eyes.

A: What is he wearing today?

B: He's wearing a white T-shirt and blue jeans.

A: 5._____________?

B: It's 13803677057.

A: OK. We'll call you as soon as we find him.

B: Thank you very much.

题型:单项选择题

食管发生的肿瘤类型中应除外()

A.腺鳞癌

B.横纹肌肉瘤

C.恶性黑色素瘤

D.鳞状细胞癌

E.浸润性导管癌

题型:单项选择题

输血可以引起哪些感染()

A.梅毒

B.丙型病毒性肝炎

C.弓形虫病

D.艾滋病

E.细胞病毒感染

题型:单项选择题

混凝土强度随下列因素的增大而增大的有( )。

A.水灰比

B.所用水泥强度等级

C.龄期

D.混凝土的质量

E.混凝土表面积

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