A：①⑤
B：③⑥
C：①②④
D：④⑥
Playing too many computer games is ____ (harm) to you.
①苹果树开花后，喷施适宜浓度的生长素可防止果实脱落
②用细胞分裂素处理马铃薯块茎，可抑制其发芽
③用一定浓度乙烯利处理采摘后未成熟的香蕉，可促其成熟
④用生长素类似物处理二倍体番茄幼苗，可得到多倍体番茄．
下列各组划线字的用法和意义，相同的一组是（ ）
–David, is that _____ English teacher?
--Yes, he is ___. He is very caring.
