正确答案: A

正确

题目：子房上位有下位花和周位花2种情况。( )

解析：A

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举一反三的答案和解析：

[单选题]若坡度从10°增大到15°，则a点的数值将

增大

[单选题]I walked slowly through the market, where people all kinds of fruits and vegetables.I studied the prices carefully and bought what I needed.

were selling

[多选题]下列关于简谐振动和简谐波的说法，正确的是

媒质中质点振动的周期一定和相应的波的周期相等

横波的波峰与波谷在振动方向上的距离一定是质点振幅的两倍。

解析：【解析】本题考查机械波和机械振动.介质中的质点的振动周期和相应的波传播周期一致A正确.而各质点做简谐运动速度随时间作周期性的变化,但波在介质中是匀速向前传播的,所以不相等,B错.对于横波而言传播方向和振动方向是垂直的,C错.根据波的特点D正确.

[单选题]What do we know about Olivetti ?

It has five independent companies with its head office in lvrea.

[单选题]The silk thread found in the hair of an Egyptian mummy suggests that .

trade along the Silk Road began earlier than once thought

[单选题]We can infer from the passage that the author ______________.

felt surprised to win the competition

解析：【解析】推理判断题。由always—always—rewarding the same old winners, I can’t say that with any certainty和I probably never…等可推断出，作者对得奖还是惊讶的。

[单选题]CPeople from East Asia tend to have more difficulty than those from Europe in distinguishing facial expressions--and a new report published online in Current Biology explains why.

pay equal attention to the eyes and the mouth