柳树的花没有鲜艳的花瓣，却能结出果实和种子，这一事实说明了（ ）A、大多数植物的花都没有花被 B、大多数植物的花只有雌蕊和雄蕊C、
．等腰三角形中，腰长为5cm，底边为8cm，则他的底角的正切值为_______.
关于温度、内能、热量三者的关系，下列说法正确是（ ）A．温度高的物体，内能一定大B．物体温度升高，一定是吸收了热量C．物体吸收了热量，
根据枸杞产量与气候条件的关系，把宁夏划为枸杞的适宜、次适宜和不适宜种植区，从而为枸杞种植的合理布局提供了参考依据。读图完成下列小题。
We know that a smile is usually a sign _____ people feel friendly and happy, but _____ we don’t know who the new person is? A. that; what if B. when; what
我国奉行独立自主的和平外交政策。这一外交政策的宗旨是（ ） A．独立自主 B．维护我国的独立
Putin will run for president next March in an election that could open the way for him to stay in ______ for 12 more years. A. power B. force
D Even a child knows that nodding(点头) the head means “Yes”. But some people will probably be puzzled when they first come to India.
