（1）基因工程的基本操作程序主要包括四个步骤，其中的核心步骤是____ ；

（2）若要将某目的基因通过农杆菌转化法导入植物细胞，先要将目的基因插入农杆菌Ti质粒的____ 中，然后用该农杆菌感染植物细胞，通过DNA重组将目的基因插入植物细胞的____ 上．植物组织培养的主要原理是植物细胞具有____ ，具体过程是在____ 和人工控制条件下，将离体的植物器官、组织、细胞培养在人工配制的培养基上，给予适宜的条件，诱导其经过____ 产生愈伤组织、丛芽，最终形成完整的植株．

（3）在哺乳动物的核转移实验中，通过一定的措施将受体细胞激活，使其进行细胞分裂和发育，当胚胎发育到____阶段时，将胚胎移入受体（代孕）动物体内．

（4）生态工程是实现循环经济最重要的手段之一，请写出它遵循的基本原理（至少答两项）：____．

    We often dine out with others, but do you know some basic etiquette (礼节)? If you behave well at the table, it will make your partners happy. But if you don't know how to behave yourself, you will feel embarrassed. Here are some tips for the table etiquette.

    When helping a woman pull her chair to the table, hold it and guide it. Don t shove(碰撞)it against the back of her legs.
     If you're seated at a table with eight or fewer guests, wait for everyone to be served and for the hostess(女主人) to begin eating before you dig in. At a long banquet table, it's OK to start when several people are seated and served.

    If you prefer not to have wine while dining out, don't turn your glass upside down, and don t make a big deal of saying you don't drink. Simply place your fingertips on the rim(边缘) of the glass and say" Not today, thanks."

    When you excuse yourself to go to the restroom, just say" Please excuse me."

    When out with friends or family—even at a fancy restaurant –it's OK to ask for your leftovers(吃剩的饭菜) to be wrapped. But don't do it at a business lunch or dinner.

Information Card

下列各句中划线的成语使用正确的一项是（    ）

    ____Friendships between Americans can be close and real, yet disappear soon if situations change. Neither side feels hurt by this. Both may exchange Christmas greetings for a year or two, perhaps a few letters for a while — then no more.____. This can be quite difficult for us Chinese to understand, because friendships between us develop more slowly but then may become lifelong feelings, extending (延伸) sometimes deeply into both families.

    Americans are ready to receive us foreigners at their homes, share their holidays, and their home life. They will enjoy welcoming us and be pleased if we accept their hospitality (好客) easily.

    There is another difficult point for us Chinese to understand.____ This is usually the opposite of the practice in our country where we may be generous (慷慨)with our time. Sometimes, we, as hosts, will appear at airports even in the middle of the night to meet a friend.____. The Americans, however, express their welcome usually at homes, but truly cannot manage the time to do a great deal with a visitor outside their daily routine. They will probably expect us to get ourselves from the airport to our own hotel by bus. And they expect that we will phone them from there.____. We will find ourselves treated hospitably(好客).

    For the Americans, it is often considered more friendly to invite a friend to their homes than to go to restaurants, except for business matters. So accept their hospitality at home!

A.Americans don't show their politeness if it requires a great deal of time.

B.Friendships between Americans usually extend deeply into their families.

C.Americans always show their warmth even if they are very busy.

D.Once we arrive at their homes, the welcome will be full, warm and real.

E.We may take days off to act as guides to our foreign friends.

F.If the same two people meet again by chance, even years later, they pick up the friendship.

G.America is a mobile society.

驿路梨花（节选）

    我们正在劳动，突然梨树丛中闪出了一群哈尼小姑娘。走在前边的约莫十四五岁，红润的脸上有两道弯弯的修长的眉毛和一对晶莹的大眼睛。我想：“她一定是梨花。”

    瑶族老人立即走到她们面前，深深弯下腰去，行了个大礼，吓得小姑娘们像小雀似的蹦开了，接着就哈哈大笑起来：“老爷爷，你给我们行这样大的礼，不怕折损我们吗”?

    老人严肃地说：“我感谢你们盖了这间小草房。”

    为头的那个小姑娘赶紧摇手：“不要谢我们!不要谢我们!房子是解放军叔叔盖的。”

    接着，小姑娘向我们讲述了房子的来历。十多年前，有一队解放军路过这里，在树林里过夜，半夜淋了大雨。他们想，这里要有一间给过路人避风雨的小屋就好了，第二天早上就砍树割草盖起了房子。她姐姐恰好过这边山上来拾菌子，好奇地问解放军叔叔;“你们要在还里长住?”解放军说：“不，我们是为了方便过路人。是雷锋同志教我们这样做的。“她姐姐很受感动。从那以后，常常趁砍树、拾菌子、找草药的机会来照料这小茅屋。

    原来她还不是梨花。我问：“梨花呢?”

    “前几年出嫁到山那边了。”

    不用说，姐姐出嫁后，是小姑娘接过任务，常来照管这小茅屋。

    我望着这群充满朝气的哈尼小姑娘和那洁白的梨花，不由得想起了一句诗：“驿路梨花处开”。