Question

The teacher, ________ that his students have difficulty in English grammar, has decided to give them some further drilling．

1. A.
   knowing
2. B.
   known
3. C.
   to know
4. D.
   being known

Answer 1

A
難。考查非謂語(yǔ)動(dòng)詞。本句的主句是The teacher has decided to give them some further drilling．中間的結(jié)構(gòu)應(yīng)該是一個(gè)可充當(dāng)狀語(yǔ)的分詞結(jié)構(gòu)，表示“當(dāng)老師知道他的學(xué)生在學(xué)語(yǔ)法上有困難時(shí)……”，是主動(dòng)形式，故用knowing。