.The first step towards _______(protect) the environment is to try to throw away less rubbish请讲的详细一些

.The first step towards _______(protect) the environment is to try to throw away less rubbish请讲的详细一些
.The first step towards _______(protect) the environment is to try to throw away less rubbish
请讲的详细一些

.The first step towards _______(protect) the environment is to try to throw away less rubbish请讲的详细一些
protecting
toward sth表示对于某市,所以要用动名词形式.