陀螺经纬仪测定的方位角是（）。 A.坐标方位角 B.磁北方位角 C.施工控制网坐标系

下列是某化学兴趣小组模仿工业上用甘蔗为原料制白糖的主要步骤：

①将甘蔗洗净、去皮、压榨得甘蔗汁，静置得糖汁．

②在糖汁中加入稍过量的碱溶液以中和其中的酸及使部分杂质形成沉淀，过滤．

③在所得滤液中通入某气体，以除去过量碱溶液，再次过滤，得滤液．

④将滤液蒸发，糖液经浓缩后冷却，有红棕色的结晶析出，便制得红糖．

⑤将红糖溶解，加入活性炭脱色、过滤、蒸发，浓缩析出白色晶体，这就是白糖．

根据以上实验步骤，回答下列问题：

（1）在过滤和蒸发过程中均用到的玻璃仪器是______．

（2）为节约成本，步骤②中所用的碱应该是______（填俗名），若②中的酸可用HA表示，则相关的化学方程式为______．

（3）关于第五步操作中说法正确的是______．（填符号）

A．红糖的溶解、吸附脱色、蒸发结晶都是化学变化

B．这样所得的白糖一定是纯净物

C．浓缩糖液到有白色晶体析出时，此时溶液为饱和溶液．

When the system upon which a transport entity is running fails and subsequently reatarts, the ___34___ information of all active connections is lost. The affected connections become half-open, as the side that did not fail does not yet realize the promble.

The still active side of a half-open connections using a ___35___ timer. This timermeasures the time transport machine will continue to await an ___36___ of a transmitted segment after the segment has been retransmitted the maximum number of times. When the timer ___37___, the transport entity assumes that either the other transport entity or the intervening network has failed. As a result, the timer closes the connection, and signals an abnormal close to the TS user.

In the event that a transport entity fails and quickly restart, half-open connections can be teminated more quickly by the use of the RST segment. The failed side returns an RST_i to every segment i that it receives. When the RST_i reaches the other side, it must be checked for validity dased on the ___38___ number i, as the RST could be in response to an old segment .If the reset is valid, the transport entity performs an abnormal termination.

38（）

A. connection

B. acknowledgment

C. sequence

D. message

衡量岩层储集性能的主要参数是（）。

A.孔隙性、溶解性

B.孔隙度、渗透率

C.溶解性、渗透性

D.有效孔隙、总孔隙

教香菱作诗的老师是（）

A、宝钗

B、黛玉

C、湘云

D、宝琴