Which of the following generalizations is supported by the passage？
A. Each time of year has its own special features.
B. As seasons change,so do people.
C. Tiny sounds can be of great importance.
D. Spring is the most beloved season of all.
Which of the following is TRUE？
A. The various petroleum products are produced by filtration.
B. Heating and condensation produce the various products.
Chemical separation is used to produce the various products.
D. Mechanical means such as the centrifuge (离心机) are used to product the various products.
Panmixia is said to_____.
A. aid the selection process
B. complement individualization
C. inspire positive results
D. set up biological decline
Which of the following best describes the spring climate of the area of the country the author is describing？
A. Cold and dry
B. Warm and humid
Cool and wet
Dry and warm
微信支付 
支付宝支付