$3.$A multimeter measures

$($a$)$ Current

$($b$)$ Voltage

$($c$)$ Resistance

$($d$)$ Current, voltage and resistance

$4.$ Two resistors of $1$ and $2$ are connected in parallel to get an effective resistance

$($a$)0\mathrm{.}67$

$($b$)0\mathrm{.}56$

$($c$)0\mathrm{.}43$

$($d$)0\mathrm{.}33$

$$wo resistors of $4$ and $2$ are connected in series to get an effective resistance

$\text{'}$a$)8$

b$)7$

$6$

$5$