小李对种子的萌发很感兴趣，于是就照着图做了以下实验：将同种具有相同、较强活力的植

老师上课时经常用到投影仪，如下图所示，关于投影仪的使用以下做法中合理的是：

A．投放到屏幕上的画面太靠上时，应增大平面镜与凸透镜的夹角使画面向下移动

B．若使屏幕上的画面大一些，可使投影仪靠近屏幕同时将凸透镜适当向下移动

C．若使屏幕上的画面大一些，可使投影仪远离屏幕同时将凸透镜适当向上移动

D．若使屏幕上的画面大一些，可使投影仪远离屏幕同时将凸透镜适当向下移动

关于荧光体的叙述，错误的是（）

A.荧光体分为单纯型和赋活型

B.稀土增感屏的荧光体是单纯型

C.赋活型由母体、赋活剂和融剂组成

D.母体是荧光体具有某种特性的基础

E.融剂有增加发光效率的作用

胎儿在母体子宫内从羊水中获取营养物质．______．

China is to send its top negotiator on North Korea’s nuclear program to Pyongyang (36) amid international concern over the launch of (37) .
While the (38) and its ally Japan push for (39) against North Korea, China is (40) , not sanctions.
Also, the (41) to Japan says sanctions on North Korea will (42) efforts to bring the secluded state back to (43) on its nuclear program.
North Korea (44) the six-party talks in (45) after Washington imposed financial sanctions for alleged counterfeiting and (46) activities.
A broadcast on North Korean State Television (47) the missile tests, in what it called a "successful (48) ".
It said North Korea will take action against anyone who (49) them.
The Minister is reported to have told a (50) that the missile launches were (51) because of America’s sanctions against Pyongyang.
North Korea remains (52) in the face of international condemnation and has warned (53) could be carried out.
UN Security Council members will (54) discussions tonight on whether a (55) condemning the missile launches should call for sanctions.

采气树笼套式节流阀后需调整至所需压力范围为（）。

A.11~19Mpa

B.19~28Mpa

C.19~22Mpa

D.8.5Mpa~11Mpa