潜能开发的要素（）A、高度的自信 B、坚定的意志 C、矛盾的激化 D、强烈的愿望

将手电筒中的小灯泡用导线与一节干电池相连时，小灯泡亮度较暗，与两节干电池相连时，小灯泡亮度较亮．由此猜想，在小灯泡电阻一定时，加在其两端的电压越大，通过的电流越______；调节台灯上电位器的旋钮，使其电阻变大，则与之串联的灯泡亮度变暗．由此猜想，在电压一定时，电路中的电阻越大，电流越______．

新生儿窒息时，首先要进行的处理是

A．清理呼吸道

B．吸氧

C．口对口人工呼吸

D．酒精擦浴

E．脐静脉推注碳酸氢钠

Kofi Annan says helping survivors of last week’ s earthquake and (1) in the Indian Ocean is (2) . The United Nations secretary- general says countries that have offered aid must (3) and provide it. The offers add up to around (4) dollars. United Nations officials say (5) of that is needed during the next six months. The concern about offers of international aid is (6) . For example, the earthquake in Barn, Iran, in (7) of 2003 killed more than (8) people. Countries and groups offered hundreds of millions of dollars (9) .The United Nations says it has (10) only about (11) dollars in aid received so far. Governments and organizations that offered help (12) that, however. On (13) Mr. Annan met with world leaders in Jakarta, Indonesia to discuss aid for (14) . The leaders discussed and (15) the idea of (16) owed by affected nations. But the leaders did not say they would do so. Some said that (17) to survivors would be more helpful. Representatives of (18) countries and international organizations attended the meeting in Jakarta. Officials say they will cooperate to develop (19) for the Indian Ocean and the (20) .

简述D-4型电铲回转拉闸的工作原理。

肉毒类毒素是肉毒梭菌产生的毒性极强的神经麻痹毒素，它是由两个亚单位即含两条肽链组成的一种生物大分子，1mg可毒死20亿只小鼠。煮沸1min或75℃下加热5～10min，就能使其完全丧失活性。可能引起肉毒梭菌中毒的食品有腊肠、火腿、鱼及鱼制品、罐头食品、臭豆腐、豆瓣酱、面酱、豆豉等。下面是肉毒类毒素的局部结构简式：

一分子肉毒类毒素至少含有（）个氨基和（）个羧基。