《国务院关于建立统一的企业职工基本养老保险制度的决定》中规定，本养老保险基金结余额，

核黄素又称为维生素B2，可促进发育和细胞再生，有利于增进视力，减轻眼睛疲劳．核黄素分子的结构为

已知：

有关核黄素的下列说法中，不正确的是（　　）

A．该化合物的分子式为C₁₇H₂₂N₄O₆

B．酸性条件下加热水解，有CO₂生成

C．酸性条件下加热水解，所得溶液加碱后有NH₃生成

D．能发生酯化反应

文件型病毒传染的对象主要是可执行文件。

在抗震设防7度地震区，建造一幢6层中学教学楼，下列中哪一种结构体系较为合理()

A．钢筋混凝土框架结构

B．钢筋混凝土框一剪结构

C．普通砖砌体结构

D．多孔砖砌体结构

Part 4

Questions 26-45

·Read the following passage and choose the best word for each space.
·For questions 26-45, mark one letter A, B, C or D on the Answer Sheet.
Do you want to send an e-mail message to the White House
Good luck.
In the past, (26) President Bush — or at least those assigned to read his mail — what was (27) your mind it was necessary only to sit down at a personal computer connected to the lnternet and (28) a note to president@ whitehouse.gov.
But this week, Tom Matzzie, an online organizer with the A.F.L.-C.I.O., discovered that (29) with the White House had become a bit more (30) . When Mr. Matzzie sent an e-mail protesting (31) a Bush administration policy, the message was bounced back With an automated reply, saying he had to send it again in a new way.
Under a system (32) on the White House Website (33) the first time last week, those who want to send a message to President Bush must now (34) as many as nine Web pages and (35) a detailed form that starts by asking whether the message sender supports White House policy (36) differs with it.
The white House says the new e-mail system is an effort to be more responsive (37) the public and offer the administration "real time" access (38) citizen comments.
Completing a message to the president also requires (39) a subject from the provided list, then entering a full name, organization, address and e-mail address. (40) the message is sent, the writer must wait for an automated response (41) his message, (42) whether the addressee intended to send the message. The message is delivered to the White House only after the person using that e-mail address (43) it.
"Over (44) , it’s a very cumbersome process," said Jakob Nielsen, an authority on Web design. "It’s probably designed deliberately to (45) on their e-mail.\

A．to choose

B．of choosing

C．choosing

D．choice

沉积在电晕极和收尘极上的粉尘必须通过（）及时清除，电晕极上积灰过多，会影响（），收尘极上积灰过多，会影响尘粒的（）。