某物种在群落中的相对多度、相对频度及相对优势度之和即为该物种在该群落中的______

德军在欧洲西部战场遭到的第一次重大挫折是： [ ]

A、敦刻尔克大撤退

B、空袭英国被挫败

C、西西底登陆战

D、诺曼底战役

在金属烤瓷桥制作中，制作金瓷交接的外形时，应考虑的因素有 （）

A.利于金属肩台承受瓷层传导牙合力

B.避免引起应力集中

C.避免锐角

D.确保瓷层有足够的厚度

E.便于操作

旅行社资产的构成特点是（）。

A.流动资产比重小

B.递延资产比重大

C.债权资产比重高

D.固定资产比重小

E.无形资产比重小

I used to work in an office, which had a Iocust tree growing outside the window. It had grown into a tall tree and must have been there for a long time. The tree blocked the view and made the office seem dull. Unfortunately, this happened to be the room assigned to me, and l was depressed by it for quite some time.

When the first spring came, everything was green except the locust tree.I felt very happy because I had thought it had died!

One morning, when I opened the window for some fresh air, I unexpectedly smelt a familiar sweet scent floating into my office which I could not name. Suddenly,I realized it was the locust tree!The tree that I thought dead was in full bloom!

From then on, I usually came to the office very early to see dew forming on the locust tree blossoms, and was eager to see spring again every year.

During summer, the green leaves provided shade protecting me from the harsh sunlight, but allowing enough light in to make it pleasant. In autumn, the leaves turned many different colors. Its beauty touched my soul. Many times, I thought to take photos but never did. Then, I had to leave in a hurry. Later in life, it became a great regret that I had not done so.

Actually, many times in our lives we think we own something and thus do not value it. We don't feel regretful until we lose it one day! Moreover, sometimes, we have to accept the things we don't want and need to discover the hidden beauty to find unexpected joy!

小题1: The locust tree first attracted the author most by____.

A．the way it blocked the view

B．its height

C．the smell of its flowers

D．its green leaves小题2:In which season do you think the author paid the least attention to the locust tree?

A．Spring.

B．Summer

C．Autumn.

D．Winter.小题3:Which of the following statements is true of the author according to the passage?

A．He would have regretted if the locust tree had died as he had thought it had.

B．The locust tree turned out to be a lovely memory for him.

C．He felt unhappy as he had forgotten to take the photos with him.

D．His work in the office changed with the seasons every year.小题4:It can be inferred from the passage that _______.

A．the locust tree died soon after the author left the office

B．the author worked in the office for at least a few years

C．it was summer when the author took his job in the office

D．the weather was dry when the author first saw the tree小题5:What advice does the author intend to give us?

A．Treasure what we've owned.

B．Look before you leap.

C．Treat everything calmly.

D．Never forget the past.

使用电动钻机时，远程控制台应摆在（）。

A、钻台后方

B、面对钻台的左侧

C、距井口25m远

D、距井口20m远

E、放喷管线的前方