以下哪项属于风热疮的临床特点()。
A.好发于儿童
B.多见于夏秋季节
C.皮损呈多形性,对称分布
D.搔抓后可见露水珠样点状出血
E.以上均不是
参考答案:E
There are many reasons for animals _____ but the most important one is the part _____ humans have played. [ ]
A. die out, that
B. dying out, that
C. died away, which
D. dying down, which
光照增强,光合作用增强,但在光照最强的夏季中午,由于气孔关闭,光合作用不继续增加,反而下降,主要原因是()
A.气温高,酶的活性受影响
B.水分减少,水分解产生的氢数量减少
C.光照太强,使色素分解
D.CO2供应减少,暗反应过程中C3产生得太少