轴的校直通常有冷校直和热校直两种方法，一般大于50mm的轴，采用（）。

有压长管道是认为水头全部消耗在沿程水头损上。

朋友有困难找你帮忙，可你没有能力帮助他，你会[     ]

A、断然拒绝

B、为了不伤害朋友，也不伤害自尊，先答应下来

C、坦诚说明理由，以求朋友谅解

D、赴汤蹈火，在所不惜

将6t石灰石充分煅烧，其中的碳酸钙全部分解后（杂质不是生石灰，也不分解），剩余固体的质量为3.8t。求剩余固体中生石灰的质量分数（计算结果精确到0.1%）

Beijing: The United States and North Korea had their first (1) in four months here this afternoon as part of the (2) negotiations on how to end North Korea’s nuclear program, but diplomats played clown prospects for (3) . The talks are at the Diaoyutai (4) , a sprawling, garden-filled (5) in western Beijing, with negotiators gathering around a giant hexagonal table built to (6) the six delegations. The Chinese placed the Americans and the North Koreans in (7) , which may have facilitated the (8) between Mr. Kelly and Mr. Kim, which took place (9) in the afternoon session. The two spoke for 30 minutes, two Asian diplomats (10) . The early indications of how the talks are going (11) . A South Korean who took part in the meetings described North Korea as "willing to (12) through dialogue." Chinese officials also put a (13) on the talks. "I heard talks this morning and this afternoon were very successful," the Foreign Minister, Li Zhaoxing, told delegates (14) . But Japanese and Russian participants were (15) . The Russian (16) , Aleksandr Losyukov, described the negotiations as (17) . "So far, the countries have put forward a number of (18) , which are (19) the development of these talks," he told Russian reporters in Beijing. "I would not say that I am feeling (20) ."

遇一女年轻病人，突然倒地，呼吸浅速，随之高叫“手麻”，手足勾屈，抽搐，迅速呼吸停止，呼之不应，检查见眼睑颤动，眼球上翻，你的急救措施应是立即（）。

A.静注安定

B.静注呼吸兴奋剂

C.人工呼吸及胸外心脏按摩

D.准备作气管切开

E.生理盐水肌注，配合言语暗示