[单项选择]How long will be the student visa valid for
A. The duration of her stay.
B. The duration of her course.
C. A period of five years.
D. A period of four years.

[单项选择]For how long is a limited license valid
A. Less than one year.
B. Four years.
C. Five years.
D. Ten years.

[单项选择]How long can a graduate student keep the borrowed books（）
A. 14 days.
B. 20 days.
C. 28 days.

[单项选择]Nobody yet knows how long and how seriously the shakiness in the financial system will the economy（）
A. knock down
B. drag down
C. settle down
D. put down

[单项选择]Nobody yet knows how long and how seriously the （）in the financial system will drag down the economy.
A. shallowness
B. shakiness
C. scantiness
D. stiffness

[填空题]

How long does it usually take a student to finish the retail floristry certificate program

[单项选择]People have wondered for a long time how their personalities and behaviors are formed. It is not easy to explain why one person is intelligent and another is not, (62) why one is cooperative and another is competitive.
Social scientists are, of course, extremely interested in these types of questions. They want to explain why we possess certain characteristics and (63) certain behaviors. There are no (64) answers yet, but two distinct schools of thought on the matter have (65) . As one might expect, the two (66) are very different from one another, and there is a great deal of (67) between proponents (支持者) of each theory. The controversy is often (68) to as "nature vs. nurture".
Those who support the "nature" side of the conflict believe that our personalities and behavior patterns are (69) determined by biological and (70) factors. That our environment has (71) , if anything, to do with o