綜合寫作：

　　The decrease of human brain

　　人腦縮小的原因

　　READING

　　3 possible explanations.

　　1.Climate change.

　　Small body can adjust to hot temperatures, so human brain shrinks in accordance with the body.

　　2.Changes of agricultural lifestyle.

　　Smaller brain fits the diet when people start eating grain, with protein and vitamin in it.

　　3.Changes in human muscle mass

　　Human muscles have shrunk, which leads to the decline of muscle-controlling brain.

　　Against.

　　反對

　　1.過去溫度也在變化，但人腦持續(xù)變大，所以人腦大小和氣溫無關

　　The size of human brain has nothing to do with temperatures. The brain keeps getting larger and large no matter temperatures go up or fall down.

　　2.有些地區(qū)最近才有生活方式的改變，但人腦變小在全球幾乎是同一時間發(fā)生，所以不可能。

　　Lifestyle appears in different times. There was no such trend in Australia and South Africa until recently. Yet the decline of human brain occurs at the same time around the world. So this assumption cannot be true.

　　3.肌肉群知識略有縮小，而人腦變小了很多，所以這不可能是主要原因。

　　The size of human muscle mass only decrease slightly, yet brain size gets much smaller. So this cannot be the major reason.