合理的间套作可有效地利用光能、地力和空间。但会加重病虫及杂草的危害。
参考答案：错
电子显微镜根据成像方式的不同可以分为透射电镜和（）两种类型。
The size of a flat-screen television is given as the length of the screen’s diagonal. How many square inches greater is the screen of a square 34-inch flat-screen television than a square 27-inch fiat-screen television ？（）
A. 106.75
B. 213.5
C. 427
D. 729
E. 1,156
