[填空题]Scientists have done a lot of study to show that praise is far （） (effective) than criticism in improving students’ behavior.

[填空题]Scientists have done a lot of study to show that praise is far ______ (effective) than criticism in improving students’ behavior.

[单项选择]Part 1We have done a lot of trade with your company for the past five years.
A. 我们公司主要经营手工艺品。
B. 在过去的五年中，我们与贵公司进行了大量的贸易。
C. 我们的目的是要为我们的产品开发海外市场。
D. 我们的目的是和你们探讨一下发展贸易的可能性。

[单项选择]

Scientists who study the brain have found out a great deal about how we learn. They have (21) that babies learn much more from the sights and sounds around them than we (22) before. You can help your baby by taking advantage of her hunger to learn.
From the (23) beginning, babies try to imitate the (24) they hear us make. They "read" the (25) on our faces and our movements. That is (26) it is so important to talk, sing and smile to your child. Hearing you talk is your baby’s first (27) toward becoming a reader, because it (28) her to love language and to learn words.

21（　）
A. discovered 
B. heard 
C. watched 
D. written

[填空题]Scientists have done countless experiments to show that praise is far( effective )（）than criticism in improving human behavior.

[单项选择]
Scientists who study insects have a real mystery on their hands. All across the country, honeybees are leaving their hives and never returning. Researchers call this phenomenon colony-collapse disorder. According to surveys of beekeepers across the country, 25 to 40 percent of the honeybees in the United States have vanished from their hives since last fall. So far, no one can explain why.
Colony collapse is a serious concern because bees play an important role in the production of about one-third of the foods we eat. As they feed, honeybees spread pollen from flower to flower. Without this process, a plant can’t produce seeds or fruits.
Now, a group of scientists and beekeepers have teamed up to try to figure out what’s causing the alarming collapse of so many colonies. By sharing their expertise in honeybee behavior, health, and nutrition, team members hope to find out what’s contributing to the de
A. Honeybees are flying all across the country.
B. 25-40 percent of the honeybees in the US have died.
C. Honeybees are leaving their hives and do not return.
D. Honeybee hives are in disorder.

[单项选择]We have done things we ought not to have done and ______ undone things we ought to have done.
A. leave
B. leaving
C. left
D. will leave