【问】 The painter Jacob Lawrence frequently incorporated patterns into his compositions，mak-ing them more striking than they would____have been.
 A. instead B. however C. otherwise D. nevertheless(TOEFL，86. 3)
 我知道答案为C(otherwise)，但我不明白，为什么than从句的谓语动词要用虚拟语气。我在英汉词典中没有查到这种用法。
 【答】 otherwise用作副词或连词时常常表示否定的条件(negative condition)。或者说，表示与前述内容相反的条件。这个否定条件可以是现实的，也可以是反现实的(假想的，虚拟的)。在前一情况下，含otherwise的分句的谓语动词用陈述语气，在后一情况下，用虚拟语气。当otherwise用作连词时，其用法和意义相当于连词or.
 1. Seize the chance，otherwise[or] you will regret it. (CGEL)
 抓住这个机会，否则你会后悔的。
 2. Don’t be too long，otherwise[or] you’ll miss the bus. (CGEL)
 时间不要拖得太长，要不然你就赶不上公共汽车了。
 3. Do it now. Other’wise，it will be too late. (LDCE)
 现在就干吧，要不然，就太晚了。
 4. The sailors would have otherwise’ fallen into the sea. (MD)
 要不然水手们早就掉进大海里去了。
 5. They (must have)liked the apartment.otherwise[or] they wouldn’ t have stayed solong. (CGEL)
 他们(一定)喜欢这个公寓，要不然他们不会住这么久的。
 6. Gas molecules move in all directions，otherwise the color could not spread throughout thejar.
 气体分子是到处运动的，不然的话，颜色就不可能扩散及整个瓶子。
 7. The atmosphere acts as a screen to shield us from certain harmful rays that would other-wise beat down on the earth and make life impossible.
 大气层象屏障一样，保护我们不受某些有害射线的照射，否则，这些有害的射线就会照射到地球上，使生物无法生存。
 8. One way is to develop uses for products which otherwise would waste.
 方法之一，就是开发那些不用就会成为废物的产品的用途。
 请做下面的英语试题：
 1. He was very busy yesterday： otherwise，he____to the meeting.
 A. would come B. came C. should come D. would have come
 2. These national parks are very important for preserving many animals，who would
 ____run the risk of becoming extinct.
 A. instead B. therefore C. nevertheless D. otherwise