[单项选择]Mr. White works with a chemicals import & export company, but he_________for this industrial fair, since he is on leave.
A. has worked
B. works
C. has been working
D. is working

[单项选择]Mr. White works with a chemicals import & export company, but he （） for this industrial fair, since he is on leave.
A. has worked
B. works
C. has been working
D. is working

[单项选择]Mr. White works for a chemicals import and export company, but he has been working for this industrial fair, while he is ______ from that company.
A. on leave
B. on duty
C. on patrol
D. on guard

[填空题]The most expensive diamonds are usually white in color.

[填空题]

A. natural ecosystems B. white pollution
C. water and soil erosion D. water resource conservation zone
E. forest coverage F. forestation project
G. environmental protection H. urban green land
I. eco-demonstration region J. develop renewable resources
K. nature reserve L. clean energy
M. endangered wildlife N. uncontrolled urbanization
O. conserve natural habitats P. conservation of water and soil

（）自然生态系统（）濒危野生动物

[填空题]

A--Import licensing B--Export restrictions
C--Technical barriers D--Subsidies
E--Voluntary export restraints F--Import prohibition
G--Sanitary and phytosanitary measures H--Tax discrimination
I--Access restrictions J--Foreign ownership restrictions
K--Anti-dumping measures L--Government procurement
M--Import quota N--Domestic content regulations
O--Customs valuation P--Export licensing

（）补贴（）外国股权的限制