各种frameworks都加了，，还是报下面这个错。。求教
Undefined symbols for architecture x86_64:
“OBJC_CLASS_EKEvent", referenced from:
objc-class-ref in GoogleMobileAds(GADOpener.o)
"_OBJC_CLASS__EKEventEditViewController”, referenced from:
objc-class-ref in GoogleMobileAds(GADOpener.o)
“OBJC_CLASS$_EKEventStore”, referenced from:
objc-class-ref in GoogleMobileAds(GADOpener.o)
objc-class-ref in GoogleMobileAds(GADSlot+MRAID.o)
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
