问题 单项选择题

用完全培养液在两个相同的容器内分别培养水稻和番茄苗,假设两植物的吸水速率相同,一段时间后,测定培养液中各种离子,与试验开始时各种离子浓度之比如图所示:

该试验的结果不能说明:()

A.植物对离子的吸收有选择性

B.水稻吸收Si的载体多

C.植物对离子的吸收与溶液中离子的浓度有关

D.植物根对水分的吸收和对矿质元素的吸收是两个相对独立的过程

答案

参考答案:A

阅读理解

D

A husband-and-wife team from California reached the Pacific Ocean after a 4,900- mile-cross

-country walk, becoming the first to backpack the American Discovery Trail in one continuous

walk. 

Marcia and Ken powers, of Pleasanton, started the travel across 13 states, through 14 national parks and 16 national forests on Feb. 27 from Cape Henlopen in Delaware. Nearly eight months later, the excited couple walked through water into the Pacific Ocean at Point Reyes, a day ahead of time. 

“We are a little sad that a great adventure is over. It was a fantastic adventure. And now we go home and just do housework. It's really sad.” Marcia, who said she's in her 50s, and her 60-year-old husband traversed cities, desert, mountains and farmland before reaching the Pacifics alone with arms around each other' s backpacks.

They overcame deep snow in the East, a quicksand in Utah, close lightning strikes in the Mid- west and strong desert sandstorms in the West while averaging 22 miles a day and taking only four days off. But they enjoyed the French history of St. Louis' the beauty of the Colorado Rockies and the kindness of strangers they met along the way. They particularly remember two brothers ---- a

doctor and dentist-------who put them up in their homes, after terrible days, and a motorcyclist who gave them water after they failed to find any on Utah's lonely Wah Wah Desert.

“Americans are truly warm-hearted and wonderful people.” Marcia Powers said. “We got to meet people that we would never meet in our daily living at home. We got to touch it with our feet and hands and smell all its scents and hear its wildlife. It' s an amazing country,” she added.

68. Which of the following about couple's walk is TRUE?

A. The walk covered more than 13 states.

B. The walk lasted about half a year.

C. The walk didn't meet any desert.

D. The walk might end before October 27.

69. The underlined word “traversed” in the third paragraph means “____________.”

A. enjoy                       B. move across, through or over

C. overcome                    D. look at

70. According to the text, we can infer that during the walk the couple __________.

A. were treated warm-heartedly by the local people

B. never stopped to have a rest

C. were ever caught in a heavy rain and became ill

D. felt the quicksand in Utah was very interesting

71. The couple went through many places except ____________.

A. big rivers       B. desert      C. hills       D. fields

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