大纲视图中，某一主标题若要降级为层次小标题，可以按（）键。
A.Tab
B.Ctrl
C.Shift
D.Alt
参考答案：A
会发生移植排斥反应的是（）
A.同种异体移植
B.同种同型移植
C.同种移植
D.自体移植
E.以上都不正确
The teacher says we _____read ______ comic books.[ ]
A. mustn't, much too
B. can't, much too
C. may not, too many
D. shouldn't, too many
