阅读下面这篇短文，短文后有2项测试任务：(1)第23～26题要求从所给的6个选项中为第2～5段每段选择1个正确的小标题；(2)第27～20题要求从所给的6个选项中选择4个正确选项，分别完成每个句子。
Singapore 1 Singapore is an independent
city-state in southeastern Asia, consisting of one major island the Singapore
Island—and more than 50 small islands, located off the southern tip of Malay.
The city of Singapore, the capital of the country, is at the southeastern end of
the Singapore Island, it is one of the most important port cities and commercial
centers of Southeast Asia. The total area of the republic is 640 sq. km. 2
Low-lying Singapore Island has no outstanding relief(轮廓鲜明的) features. A
central area of hills rises to the maximum height of 176m. The country has a wet
tropical climate, with an average annual temperature of 27.2℃: The average
annual rainfall is 2,4t3 mm; the wettest months are November through
January. 3 Singapore is governed under a constitution of 1959, as
amended (修正后的). A president, elected to a four-year term, is head of state, and
a prime minister is head of government. The president used to be elected by
Parliament, but by a 1991 constitutional amendment (修正), the president is now
elected directly by the people. The Parliament is the lawmaking body with its 81
members popularly elected. 4 In the late 1980s the country had some 290
primary schools with 278,300 pupils and 160 secondary schools with 200,200
students. The main institutions of higher education are the National University
of Singapore (founded in 1980 with the combination of two major universities),
several technical colleges, and a teachers college. 5 Singapore has one
of the highest standards of living of any country in Asia. In the late 1980s the
gross domestic product was estimated at ＄23.7 billion, or ＄8,870 per person. The
fishing industry is centered on the port of During, on southwestern Singapore
Island. Industry has grown rapidly since the 1960s, and Singapore now produces a
diversity (多样化的) of goods, including chemicals, electronic items, clothing, and
processed foods, etc. Shipbuilding and petroleum refining are also
important. The president is elected directly by the people by a ______.