| I | confound |
|---|---|
| you | confound |
| he/she/it | confounds |
| we | confound |
| you | confound |
| they | confound |
| I | confounded |
|---|---|
| you | confounded |
| he/she/it | confounded |
| we | confounded |
| you | confounded |
| they | confounded |
| I | have | confounded |
|---|---|---|
| you | have | confounded |
| he/she/it | has | confounded |
| we | have | confounded |
| you | have | confounded |
| they | have | confounded |
| I | had | confounded |
|---|---|---|
| you | had | confounded |
| he/she/it | had | confounded |
| we | had | confounded |
| you | had | confounded |
| they | had | confounded |
单语范例（未经PONS编辑处理）
However, confounding may decrease internal validity of a study, and ethical issues may arise in studies involving high-risk.
en.wikipedia.org In answer to his pleas, she uses his own recent arguments to confound him.
en.wikipedia.org Due to the inability to control for variability of volunteers and human studies, confounding is a particular challenge.
en.wikipedia.org Confounding the definitional problem is that state and government are often used as synonyms in common conversation and even some academic discourse.
en.wikipedia.org In actual war, the target resists strategy and counters it, confounding plans, and redirecting strategy and policy to suit the unanticipated requirements for operational success.
en.wikipedia.org