A．4 mol ATP
B．3 mol ATP
C．2 mol ATP
D．1 mol ATP
参考答案：D
a﹣3与a+1互为相反数，那么a=_________．
. We’d like to do _______ we can _________ the poor.
A．how; help
B．whatever; to help
C．whatever; help
D．however; to help
