问题 选择题

在探究植物光合作用的实验中,选择银边翠、银边天竺葵做实验材料,适宜研究下列哪一个实验假设?(  )

A.水是光合作用的原料

B.二氧化碳是光合作用的原料

C.叶绿体是光合作用的场所

D.光是光合作用的条件

答案

由光合作用的概念可知:光合作用的原料是二氧化碳和水、产物是淀粉等有机物和氧气、条件是光、场所是叶绿体,可以分别通过实验加以验证;银边翠、银边天竺的叶的银边部分不含叶绿体,因此叶的银边部分和绿色部分就以叶绿体为变量形成了一组对照实验,用来验证光合作用的场所是叶绿体.

故选:C

选择题
单项选择题

Once upon a time, innovation at Procter & Gamble flowed one way: from the United States outward. While the large Cincinnati-based corporation was no stranger to foreign markets, it usually sold them products that were already familiar to most Americans. Many Japanese families, for instance, swaddle their babies in Pampers diapers, and lots of Venezuelans brush their teeth with Crest. And of course (company executives assumed) Americans at home wanted these same familiar, red white-and-blue brands. We might buy foreign-made cars, or chocolates, or cameras—but household cleaners and detergents.9

Recently, however, P&G broke with this long-standing tradition. Ariel, a P&G laundry detergent, was born overseas, and is a familiar sight on store shelves in Europe and Latin America. Now bilingual packages of Ariel Ultra, a super-concentrated cleaner, are appearing on supermarket shelves in Los Angeles.

Ariel’s appearance in the United States reflects demographic changes making Hispanics the nation’s fastest-growing ethnic group. Ariel is a hit with this population. In fact, many Mexican immigrants living in southern California have been " importing" Ariel from Tijuana, Mexico. "Hispanies knew this product and wanted it," says P&G spokeswoman Marie Salvado. "We realized that we couldn’t convince them to buy our other laundry detergents. " P&G hopes that non-Hispanic consumers will give Ariel a try too.

Ariel’s already p presence in Europe may provide a springboard for the company to expand into other markets as well. Recently P&G bought Rakona, Czechoslovakia’s top detergent maker. Ariel, currently a top seller in Germany, is likely to be one of the fast new brands to appear in Czech supermarkets. And Ariel is not tile only foreign idea that the company hopes to transplant back to its home territory. Cinch, an all-purpose spray cleaner similar to popular European products, is currently being test-marketed in California and Arizona. Traditionally Americans have used separate cleaners for different types of surfaces, but market research shows that American preferences are becoming more like those in other countries.

Insiders note that this new reverse flow of innovation reflects more sweeping changes at Procter & Camble. The firm has hired many new Japanese, German, and Mexican managers who view P&G’s business not as a one-way flow of American ideas, but a two-way exchange with other markets. Says Bonita Austin of the investment fin Wertheim Schroeder, " When you met with P&G’s top managers years ago, you wouldn’t have seen a single foreign face; today, they could even be in the majority. "

As Procter & Gamble has found, the United States is no longer an isolated market. Americans are more open than ever before to buying foreign-made products and to selling U S-made products overseas.

The word "insider" (para. 5) most probably refers to someone()

A. who buys both Ariel and Cinch

B. who works within the company or knows it fairly well

C. who is a loyal customer of Ariel

D. who once worked within Rakona