航向稳定性是指直航船受外力干扰而偏离航向，外力消失后：（）.A.操舵使船舶恢复原航向

下列事件是必然事件的是[ ]

A.明天是晴天

B.打开电视，正在播放广告

C.两个负数的和是正数

D.三角形三个内角的和是180°

根据短文内容及首字母提示，填写所缺单词。

How to be a Green One

What does it mean to be green? “Green is more than just a c 76  .It also means taking special steps to protect the e77  --the water, the land , and the air we breathe. Why is green? Plants are green, and w78  them the earth wouldn’t be such a lovely home for human beings(人类). Here’s a four-step guide to be green:

R79  It!

When you use less of something, you do a good thing for the earth. For example, a shorter shower means you use less water and less fuel(燃料) because your house uses fuel to run the water heater（加热器）that warms up the water.

Reuse It !

Sometimes we’re a little too willing to throw away the w80 and buy new things. Many times, you no l 81  need something, someone else just might need it. For example, if your baby brother grows out of toys, why not give them to a82  family who has a little kid?

Recycle(回收) It!

Recycling has n83 been easier. Many people will pick it up right in front of your house and they will need it. Tell your mum or dad become “Head of Recycling” for your house.

Enjoy It!

It’s true that p84  is a problem, but the earth is still a large and beautiful place for you to go and study. You can start by v85  the beautiful places in you home town. Go for a hike, visit local nature centres and gardens, climb up mountains and so on.

细胞间兴奋的化学传递特点，错误的是()

A．主要通过化学递质

B．不需Ca参与

C．兴奋呈单向传递

D．有时间延搁

E．易受药物和其他因素的影响

润滑油代号指40℃时的运动粘度值。

男性，38岁。突发撕裂样胸背部痛伴大汗，心率100次/分，右上肢BP100/60mmHg，左上肢BP150/70mmHg。听诊闻及颈部血管杂音，胸骨左缘第3～4肋间叹气样舒张期杂音。心电图示窦性心律，Ⅱ、Ⅲ、aVF导联T波倒置。X线胸片示上纵隔稍宽。经服用硝酸甘油疼痛未缓解。

目前最紧要的治疗是（）

A.镇静止痛

B.有效控制血压

C.强心利尿

D.继续静脉给予硝酸甘油

E.给氧