▲ 下篇短文共有 5 個空格，為第 21 － 25 題，請依短文文意，選出一個最適合該空格的答案。       Taiwan’s east coast offers marvelous views of ocean wildlife. The chances of seeing a whaleare very high in summer. It’s rather easy to spot whales, __21__ whales swim past Taiwan’s eastcoast every year between April and October. Today, whale watching __22__a popular activity.The best time for whale watching is from June to August__23__ the sea is calm. Whale watchingmakes up a major part of the tourism industry in Yilan, Taitung and Hualien counties. Whalewatching tours have been__24__ since 1997, and boat trips have been increasing. Tour operatorsare expected to follow regulations governing the activity. For example, to get a closer look at thewhales, boats should__25__ the animals from behind. A list of responsible whale watchingprinciples is included in an official guide to reduce the impact of tourism on the behavior of theworld’s biggest animals.
【題組】21.
(A) for
(B) nor
(C) so
(D) yet