Find the missing terms:
$bc\underline {} aa\underline {} dab\underline {} daa\underline {} da\underline {} c\underline {} a$.

Hint: Pattern repeats certain steps or procedure again and again. So, check the given pattern and follow the certain procedure accordingly. We have to fill the missing blanks in such a way that the pattern remains the same.

Complete answer:
Here, we will proceed with trial and error method using alphabets such as a, b, c and d.
So, place the alphabet “d” in the first blank
Therefore, the given pattern becomes –
$bc\underline d aa\underline {} dab\underline {} daa\underline {} da\underline {} c\underline {} a$
Similarly, fill the second blank with the alphabet “c”
$bc\underline d aa\underline c dab\underline {} daa\underline {} da\underline {} c\underline {} a$
So from the above fill ups we can observe that two terms are repeated alternatively.
Accordingly,
bcda/acda/bcda/acda/bcda
Hence the required solution is –

$bc\underline d aa\underline c dab\underline c daa\underline c da\underline b c\underline d a$

Note: Generally, the pattern refers to the usual types of procedures or the rules that can be followed. It is useful to predict what came before and what it might be. Whereas, the sequence is a set of numbers that are arranged in particular order.