【单选题】
对于永久荷载效应对结构构件的承载力不利的情况，若永久荷载效应在极限状态设计表达式中起来控制作用是，荷载的分项系数取为（）
①
<imgwidth="56"height="24"v:shapes="_x0000_i1030"src="http://wljy.whut.edu.cn:80/uploadfiles/word/GCJG1.files/image012.gif">,<imgwidth="56"height="25"v:shapes="_x0000_i1031"src="http://wljy.whut.edu.cn:80/uploadfiles/word/GCJG1.files/image014.gif">
②
<imgwidth="65"height="24"v:shapes="_x0000_i1032"src="http://wljy.whut.edu.cn:80/uploadfiles/word/GCJG1.files/image016.gif">,<imgwidth="56"height="25"v:shapes="_x0000_i1033"src="http://wljy.whut.edu.cn:80/uploadfiles/word/GCJG1.files/image014.gif">
③
<imgwidth="54"height="24"v:shapes="_x0000_i1034"src="http://wljy.whut.edu.cn:80/uploadfiles/word/GCJG1.files/image018.gif">,<imgwidth="54"height="25"v:shapes="_x0000_i1035"src="http://wljy.whut.edu.cn:80/uploadfiles/word/GCJG1.files/image020.gif">
④
<imgwidth="56"height="24"v:shapes="_x0000_i1036"src="http://wljy.whut.edu.cn:80/uploadfiles/word/GCJG1.files/image012.gif">,<imgwidth="54"height="25"v:shapes="_x0000_i1037"src="http://wljy.whut.edu.cn:80/uploadfiles/word/GCJG1.files/image023.gif">