1.Yet a great many processes depending on such research are sought for with complete secrecy until the stage at which patents can be taken out.
depend on 依赖，依靠；取决于，随……而定
例句：He is kind of person you can safely depend on .
他是你保险可以信赖的一种人。
a great many 许许多多，非常多
例句：Large cities are powerful magnets attracting a great many people.
大城市像巨大的磁铁一样吸引着无数人。
2.This applies particularly to chemical industries, where chance discoveries play a much larger part than they do in physical and mechanical industries.
apply to 将……应用于
例句：He applied his mind to the difficulty.
他用心解决这个难题。
play a part 扮演一个角色，参与，装腔骗人
例句：He played a leading part in solving the problem.
他在解决这个问题方面起了主要作用。
3. Many firms, for instance, have great difficulty in obtaining technical or scientific books from libraries because they are unwilling to have names entered as having taken out such and such a book, for fear the agents of other firms should be able to trace the kind of research they are likely to be undertaking.
for instance 例如，譬如，比如，比方说
例句：Take general elections for instance.
比如讲普选
For instance, you don't often see stray cattle roaming the countryside.
例如，你不会经常看见走失的牛群在村里闲逛。
have difficulty in doing
have difficulty /trouble/problem (in) doing
have作有解时，后接情感名词(in可省略)，再接动名词。这类词还有trouble, fun, a hard time, a good time。
例如：We had difficulty (in) carrying out the plan．
我们执行计划有困难。
for fear起连词作用，fear后省略了that，引导目的状语从句。这从句中常用虚拟语气。
又如：
He handled the instrument with care for fear（that）it should be damaged.
他小心翼翼地处置这仪器，生怕给弄坏了。
