语法填空（每小题1分，满分10分）
阅读下面材料，在空白处填入1个适当的单词或括号内单词的正确形式。
Many English language learners believe that the   1   (great) difficulty with listening comprehension (理解) is that the listener cannot control how quickly a speaker speaks. They feel that what the speaker says disappears ___2___ they can follow. This frequently means that students   3   are learning to listen cannot keep up. They are so busy working out the meaning   4   one part of what they hear that they miss the next part. Or they ___5__(simple) ignore a whole section because they fail to catch it quickly enough. Another difficulty is that the listener is not always in a position to get the speaker to repeat what has been said. And, of course, repeats cannot ___6___ (ask) for when listening to the radio or watching TV.
Besides,   7   (choose) of vocabulary is in the hands of the speaker, not the listener. Very often, for people listening to a foreign language, an unknown word can be like a suddenly   8   (drop) stone making them stop and think about the meaning of the word,   9   (cause) them to miss the next part of the speech. In listening, it really is a case of ＂He who   10   (stop) to work out the meaning is lost＂.