A-A+
A．Caterpillars chewing on its leavesB．Wasps la
问题详情
A．Caterpillars chewing on its leaves
B．Wasps laying eggs on its leaves
C．Pesticides sprayed on its leaves
D．Knives cutting its stalk
参考答案
正确答案：A
解析：What causes the corn plant to emit the chemical signal?
