装置紧急停工，首先要（）。 A.停原油泵 B.加热炉熄火 C.停塔底泵

下列离子组一定能大量共存的是

A．甲基橙呈黄色的溶液中：I^-、Cl^-、NO₃^-、Na⁺

B．滴加无色酚酞后仍为无色的溶液：Na^＋、CO₃^2－、K^＋、ClO^－、SO₄^2－

C．由水电离的c(OH^－)=10^－14mol·L^－1的溶液：NO₃^-、SO₄^2－、Na^＋、K^＋

D．含大量Al³⁺的溶液中：K⁺、HS^-、NO₃^-、ClO^-

关于月经不调的治疗，以下哪项叙述不当：

A．治疗主取任脉、足三阴经

B．关元、气海等是治疗月经不调的主穴

C．月经不调属于虚证，毫针刺当用补法

D．可以酌情用灸法

E．可以选用耳针治疗

配制50g质量分数为5％的氯化钠溶液，下图是某同学配制溶液的操作过程：

(1)写出标号①～④各仪器的名称：①____________；②___________；③___________；④_________。

(2)B操作中应称氯化钠的质量是______________g，称量时若指针偏右，应进行的操作是____________________________。

(3)D操作中仪器③的规格应为______________(填“10mL”、“50ml”或“100mL”)读数时应使视线与____________________________保持水平。

(4)E操作的作用是____________________________。

(5)下列错误操作可能导致溶质质量分数偏低的是______________。(填序号)

①B操作中砝码和氯化钠放错托盘 ②D操作中仰视凹液面的最低处读数

③D操作时有少量水溅出 ④F操作中溶液洒落

Instead of hitting the beach, fourteen high school students traded swimming suits for lab coats last summer and turned their attention to scientific experiments.

The High School Research Program offers high school students guidance with researchers in Texas A&M’s College of Agriculture and Life Sciences. Jennifer Funkhouser, academic adviser for the Department of Rangeland Ecology and Management, directs this four-week summer program designed to increase understanding of research and its career potential.

Several considerations go into selecting students, including grades, school involvement and interest in science and agriculture. And many students come from poorer school districts, Funkhouser says, “This is their chance to learn techniques and do experiments they never would have a chance to do in high school.”

Warner Ervin of Houston is interested in animal science and learned how to tell male from female mosquitoes(蚊子）.His adviser, Craig Coates, studies the genes of mosquitoes that allow them to fight against malaria and yellow fever. Coates thought this experience would be fun and helpful to the high school students.

The agricultural research at A&M differs from stereotypes. It’s “molecular(分子）science on the cutting edge,” Funkhouser says. The program broadened students’ knowledge. Victor Garcia of Rio Grande City hopes to become a biology teacher and says he learned a lot about chemistry from the program.

At the end of the program, the students presented papers on their research. They’re also paid $600 for their work-another way this program differs from others, which often charge a fee.

Fourteen students got paid to learn that science is fun, that agriculture is a lot more than milking and plowing and that research can open many doors.

小题1:The research program is chiefly designed for  _______.

A．high school advisers from Houston

B．college students majoring in agriculture

C．high school students from different places

D．researchers at the College of Agriculture and Life Sciences小题2:It can be inferred from the text that the students in poorer areas  ___________ .

A．had little chance to go to college

B．could often take part in the program

C．found the program useful to their future

D．showed much interest in their high school experiments小题3:When the program was over, the students  ________.

A．entered that college

B．wrote research reports

C．paid for their research

D．found way to make money小题4:The underlined expression “on the cutting edge” in paragraph 5 means “on the most  ___ position”.

A．important

B．favorable

C．astonishing

D．advanced

影响种子发芽的因素有那些？