I don’t doubt _____ he took the first place in his class; but I do doubt _____ he will succeed in the end. [ ] A .if; that B. but; which C. whether; whether D. that; whether
【简答题】Please introduce a tourist destination that you'd like to share with others. You may use slide show to illustrate it, and the duration should be no more that 2 minutes. Name your PPT with your name+st...
【单选题】Soil colloids are negatively charged, so when the following fertilizers with the same total nitrogen content are applied in the soil, the fertilizer efficiency is the worst.