高二上英语周报第二期答案

18.若选择①,b=c,则在△ABC中B=C=-,A由正弦定理得csin a sin C√3在△ABD中,由正弦定理BD即立BD,解得BD=sin∠ 1DB sin A√3sin∠ABD4)2222所以S△ABD-2AB x BD x sin∠ABD若选择②,2 bcos c+√c=2a,则2 esin bcos c+√sinC=2sinA=2sin(B+O),化简得√5smc=2 os Bsin C,因为C∈(0.5),所以smC>0,故csB=√3又B∈0-,故B6,所以A=2x由正弦定理sin a sin C在△ABD中,由正弦定理BD,即3=BD,解得BD=sin∠ ADB sin A√√LABD=sin I= sin(x-z)=v3xV2-1xV2- 6-v2所1、) Bx BDxsin∠ABDs3-5

第二节参考范文Don t panic. You ll be all right. Ill take you and your son to the hospital. said the driver. The womancould not walk, so the driver and I held her and settled her in his truck. Meanwhile, the motorcyclist carried theoy to the truck. The driver asked me to go along with them so that I could help when we got to the nearesthospital. It was a coincidence that the motorcyclist s mother was being treated in the same hospital.The driver. the motorcyclist and I got them to the hospital just in time. The motorcyclist stayed in thehospital to take care of the woman and his mother. A few days later. I was told that the woman had sufferedonly minor injuries from the incident. She had recovered and left hospital. Thanks to the kind-hearted driverher unborn baby was unharmed. The motorcyclist s mother also recovered soon. This thing has convinced mothat safety and health are the most important at all times, even in an emergency

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