国际航空协会是各国航空运输企业之间的联合组织。( )

患者女性，35岁。主因左下颌区无痛性肿胀1年就诊，无左下颌疼痛及麻木。临床检查见左下颌角明显膨隆，皮肤色、温均正常，无波动感。口内左磨牙区龈颊沟丰满，舌侧膨隆明显，触有乒乓球感，黏膜无破溃 。

对于该患者下一步要作的最有意义的检查是 （）

A.针吸细胞学检查

B.普通X线片检查

C.取活检

D.B超检查

E.穿刺检查

相同重量的铁块(γ=7.65×104N/m³)和铝块(γ=2.64×10⁴N/m³)放入水中后的重量不变。( )

There are three kinds of goals: short-term,medium-range and long-term goals. Short-range goals are those that usually deal with current activities,which we can apply on a daily basis.Such goals can be achieved in a week or less,or two weeks,or possible months.It should be remembered that just as a building is no per than its foundation ,out long-term goals cannot amount to very munch without the achievement of solid short-term goals.Upon completing our short-term goals,we should date the occasion and then add new short-term goals that will build on those that have been completed.

The intermediate goals bukld on the foundation of the short-range goals.They might deal with just one term of school or the entire school year,or they could even extend for several years.Any time you move a step at a time,you should never allow yourself to become discouraged or overwhelmed. As you complete each step,you will enforce the belief in your ability to grow adn succeed.And as your list of completion dates grow,your motivation and desire will increase.

Long-range goals may be related to our dreams of the future. They might cover five years or more. Life is not a static thing.We should never allow a long-term goal to limit us or our course of action.

Our long-term goals mean a lot（）.

A.if we complete our short-range goals

B.if we cannot reach solid short-term goals

C.if we write down the dates

D.if we put forward some plans

有机物一般不导电、难溶于水，其化学反应速度一般比较慢，同时常伴有副反应。它具有这些特点的根本原因是（）。

A.有机物分子较大

B.碳元素不易氧化

C.有机物中有氢键存在

D.有机物中原子以共价键相结合