第28题 (2.0) 分 Not until the early years of the 19th century（） what heat is.
A、man knew B、didn’t man know C、man did know D、did man know 第29题 (2.0) 分 If we work with a strong will,we can overcome any difficulty,（） great it is.A、what B、how C、however D、whatever 第30题 (2.0) 分 It can take up three months to（） a man to do this work.A、guide B、raise C、train D、learn 第31题 (2.0) 分 “Which of these two ties will you take?” “I’ll take to give me a change sometimes.” A.either B.both C.neither D.all A、either B、both C、neither D、all 第32题 (2.0) 分（）took us several hours to clear the snows and open the road to traffic.A、They B、All C、He D、It 第33题 (2.0) 分 He didn’t know what（） while he was away from home.A、would happen B、happened C、had happened D、happens 第34题 (2.0) 分 Everyone else was killed in the accident.I was the only one to（）.A、relieve B、alive C、release D、survive 第35题 (2.0) 分 Don’t be too（） about things you are not supposed to know.A、strange B、amusing C、curious D、conscious