如图是生态系统的能量流动图解，对此图解的理解错误的是（　　）

“嫦娥三号”依靠____（选填“电磁”或“声”）波将拍到的月貌图片传回地球，此波由真空进入大气的传播过程中，保持不变的是____（选填“速度”或“频率”）．

下图是“我国四大地理区域”及“甲、乙、丙三地气候资料” 示意图，读图完成下列各题。

先通读下面短文，掌握大意，然后从下面四个答案中选择可以填入相应空白处的最佳答案。
Li Hua is thirteen years old. He’s a   【小题1】 . He’s the only child in the family. He doesn’t   【小题2】 his things.
One morning when the students of Class Two are   【小题3】 an English class, Li Hua goes to the door and says, “   【小题4】  I come in, Mr. Wang ?”
“Oh, you are  【小题5】 again,” says the teacher, “Can you tell me why you are late ?”
“My grandma  【小题6】 some apples, bananas and bread in my schoolbag this morning. I take the schoolbag with me after I have【小题7】. But   【小题8】 my way to school, I find there are no  【小题9】 in my schoolbag. I have to  【小题10】 and take them.”

【小题11】	A．teacher B．girl C．student D．children
【小题12】	A．look at B．look like C．look for D．look after
【小题13】	A．having B．singing C．reading D．working
【小题14】	A．May B．Should C．Must D．Will
【小题15】	A．early B．right C．late D．busy
【小题16】	A．gives B．puts C．takes D．gets
【小题17】	A．breakfast B．lunch C．supper D．bread
【小题18】	A．in B．at C．for D．on
【小题19】	A．oranges B．water C．books D．pears
【小题20】	A．get back B．return home C．go to school D．come back

___ we know some basic knowledge concerning AIDS, we can protect ourselves from being infected.