【问】 语法书上讲lest从句中只能使用助动词should+动词原形和现在时虚拟式。是这样吗?
 【答】 许多辞典和语法书只列举了lest从句使用助动词should+动词原形和现在时虚拟语气的例句。
 1 .He ran away lest he should be seen.
 他跑开了，以免被看见。
 2. Be careful lest you fall.
 小心点儿，别跌倒。
 3. Earthen mounds were being hastily erected lest an attack should be launched that night.(CGEL)
 人们急急忙忙地堆土堆，以防夜间敌人发动进攻。
 4. The animals must be destroyed lest the disease(should) spread.(CGEL)必须把这些动物消灭掉，以防此病蔓延。
 5. I’ll be kind to her lest she decide to leave me.(LDCE)
 我将会对她很好，以免她决定离开我。
 但是，实际上有时也可以见到lest从句使用陈述语气的例子：
 1. I had to grab the iron rail at my side lest I slipped.
 我不得不抓住我这一侧的铁栏杆，以防滑下去。
 2. He wouldn’t put the letter in his pocket lest he forgot about it.
 他不把那封信放在衣袋里，为的是怕把那封信给忘了。
 考生应当注意，各类英语考试的测试专家们只承认lest he(should)do的用法。
 请做下面的英语试题：
 1. I punish the child____he should make the same mistake.
 A. unless B.because C.as D.lest
 2. They criticized him____he should make the same mistake again.
 A. unless B.so that C. lest D. in case of