下列何种放射剂量定为肿瘤致死量（）。 A.达到95%肿瘤控制率的剂量 B.达到90%

土地价格按其使用目的分类，可分为( )。

A．买卖价格、租赁价格、抵押价格、课税价格、征地价格
B．拍卖价格、招标价格、协议价格、挂牌价格
C．生地价格、熟地价格、毛地价格、净地价格
D．土地总价格、单位面积地价、楼面地价

下列各组离子中，一定能大量共存的是              （     ）   

A．加入铝粉只有氢气产生的溶液中：Na⁺、SO₄^2-、NO₃^-、Mg²⁺、

B．滴加石蕊试液显红色的溶液中：Fe³⁺、NH₄⁺、Cl^-、SCN^-

C．在0.1mol/L的NaHSO₄溶液中：NH₄⁺、Na⁺、Al³⁺、Cu²⁺、NO₃^-

D．在0.1mol/L的ＮaHCO₃溶液中K⁺、Al³⁺、Fe³⁺、NO₃^-

在探究“绿叶在光下制造有机物”时，因受时间和条件的限制，教材为我们提供了实验方案，但实验要在认同实验原理的前提下进行，以下是某小组同学在实验前依次进行的对话，请分析其中蕴含的科学思维和方法。

(1)乙同学提出的实验方法在科学研究中称之为__________，实验的变是____________。

(2)甲同学提出的检验方法，应该是受“__________”实验的启发，利用了____________的特性。

(3)丙同学是对实验结果的猜测，猜测或假设一般是根据____________作出的。

(4)丁同学的观点是消除叶中原有淀粉和__________对实验结果的影响，体现了实验的科学性。消除叶片中原有淀粉的方法是_______________。

Washington: The Bush administration has ______ for the first time that it may be willing to ______ a multinational force in Iraq to operate under the ______ of the United Nations as long as ______ by an American. The idea was described by Richard L.Armitage, the deputy secretary of state, as just"______" in discussions at the United Nations. It was first ______ publicly last week by Kofi Annan, the United Nations’ secretary general. Mr. Armitage’s remarks, made ______ to regional reporters and released by ______ today, represent ______ in course for the administration, which has until now insisted that all ______ matters in Iraq remain under total American control. Allowing the United Nations ______ would be intended to win the support of the Security Council for ______ authorizing the occupation of the country. In his remarks, Mr. Armitage ______ to discuss the plans ______, saying, "I don’t think it helps to ______ publicly fight now." But he described the arrangement under consideration as "a multinational force ______ "in which "the American would be the U.N. commander." On Monday, Defense Secretary Donald H. Rumsfeld was asked whether he could ______ American troops fighting ______ . His answer: "I think that’s not going to happen." But he went on to rule out only ______ meaning by the United Nations, whose troops wear blue helmets over a peacekeeping force in Iraq.

抓铲挖土机适用于开挖的土方是下列的( )。

A．山丘土方

B．场地平整土方

C．大型基础土方

D．水下土方