About Past Simple and Present Perfect, 

A. -Which of the following expressions are used with the past simple and which are used with the present perfect? Which are used with both?

The past simple: Yesterday, last year, six months ago, in 2010,

Present perfect: this week, yet, ever, recently

Both: yet, ever, last year

B. Complete this short business brief about Vietnam using the past simple or the present perfect forms of the verbs in brackets.

Vietnam goes through many changes in its history and experienced many economic changes recently. It is currently experiencing an economic boom. In 1986, the government introduces economic reforms or doi moi (doi meaning change and moi new).  The reforms permit the setting up of free market enterprises and abolish the practice of collective farming. However, agriculture remains the most important part of the economy. Vietnam recently becomes the second largest producer of rice in the world after Thailand. The industrial sector showed dramatic improvement and expansion as well. In 1993, the World Bank declares 58% of the population to be living in poverty. By 2005, this figure was less than 20%. Vietnam also makes great strides on the international stage in the last decade or so. It became a full member off ASEAN in 1995, and of the WTO in 2006. The effects of this new-found prosperity can be seen everywhere. Large, glitzy malls appear in major cities, while streets once filled with bicycles are now overflowing with locally produced Japanese, Korean and Chinese motorbikes and cars. Business visitors wishing to relax in a more traditional Vietnamese town should visit Hoi An. Hoi An was a major Asian trading port in the 17^th and 18^th centuries, and its picturesque architecture and relaxed lifestyle changes little over the years.