最佳答案:I must work hard; I must cheer up; I must persist.
最佳答案:It is necessary for you to concentrated in study
最佳答案:选C首先,句中出现“必须”,对应答案中,must强调必须做,而can是表示能够做...所以排除A、B其次,both与动词连用时,大多数放在系动词be之后,其他动
最佳答案:The minister says that we must keep what we are discussing under secret
最佳答案:hello,i am express transportation,we must you provide the recipient's telephone
最佳答案:I awake light-hearted this morning of spring, everywhere round me the singing of