I______to him because he phoned me shortly afterwards A.ought to have writtenB.couldn "t have writtenC.must have writtenD.needn "t have written请帮忙给出正确答案和分析,谢谢!
Vitamin E is______ A.very popular among some peopleB.effective in memory enhancementC.very helpful to the elderly actionsD.destructive in aging and cancers请帮忙给出正确答案和分析,谢谢!