月经周期第1～4日是月经期，此时雌、孕激素水平是（） A.不变 B.上升 C.雌激素

物理课上，老师做了一个奇妙的“跳环实验”。如图，她把一个带铁芯的线圈I、开关S和电源用导终连接起来后。将一金属套环置于线圈L上，且使铁芯穿过套环。闭合开关S的瞬间，套环立刻跳起。某司学另找来器材再探究此实验。他连接好电路，经重复试验，线圈上的套环均末动。对比老师演示的实验，下列四个选项中，导致套环未动的原因可能是

A.线圈接在了直流电源上

B.电源电压过高

C.所选线圈的匝数过多

D.所用套环的材料与老师的不同

根据课文内容完成下面的语法填空，注意单词拼写和词语用法。

     1_____ the morning of 19th January I went snorkeling. 2_____ (see) such extraordinary beauty, I thought

every cell in my body woke up and 3_____ was like discovering a whole new dimension of life. During the trip,

I first became aware of the vivid colors 4_____ (围绕) me and the fantastic corals, in and around 5_____ all

kinds of elegant fish 6_____ (be) swimming among them. 7_____ there are still something 8_____ made me

feel 9_____ (害怕). For example, I didn't want to get close to the eel, the giant clam and the grey reef sharks,

for they made me scared to death 10_____ a moment.

商品的边际效用随着商品消费量的增加而（）。

A.递增

B.递减

C.先减后增

D.先增后减

海洋生态治理

宫颈糜烂患者妇科检查应可见

A．宫颈外口突出单个或多个舌样、鲜红赘生物

B．宫颈 * * 部呈细颗粒状的红色区

C．宫颈表面有略突出表面的青白色小囊肿，内含黄白色黏液

D．比正常宫颈增大，质硬

E．宫颈口充血发红，宫颈外口有脓性分泌物