This is discussed under Adjustments in Connected Speech, page 4. /t,d/ disappears if it is in the middle of a 3-consonant cluster. "attract dangerous", I'd still pronounce a weak "c".
Also someone was asking if "o" can be omitted in "memory" last time, I believe so (as described under "unstressed medial vowel loss"). You can also check Webster.
Course handouts can be downloaded from http://ocw.mit.edu/courses/foreign-languages-and-literatures/21f-223-listening-speaking-and-pronunciation-fall-2004/download-course-materials/